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Heterochronic Serum Proteins, Jeffrey Mason Sep 2023

Heterochronic Serum Proteins, Jeffrey Mason

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Mechanism of ovarian-dependent enhancement of health and longevity in postreproductive female mice


Dynamic Fecal Microbiota Transfer From Mice With Western Diet-Induced Severe Colitis And Colon Tumorigenesis Did Not Exacerbate Colitis Symptoms Or Colon Tumorigenesis In Recipient Mice Fed Either The Ain93g Diet Or The Total Western Diet, Abby D. Benninghoff Jan 2023

Dynamic Fecal Microbiota Transfer From Mice With Western Diet-Induced Severe Colitis And Colon Tumorigenesis Did Not Exacerbate Colitis Symptoms Or Colon Tumorigenesis In Recipient Mice Fed Either The Ain93g Diet Or The Total Western Diet, Abby D. Benninghoff

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Consumption of the total Western diet (TWD) in mice has been shown to increase gut inflammation, promote colon tumorigenesis, and alter the fecal microbiome composition in mice as com-pared to mice fed a healthy diet, AIN93G (AIN). However, it is unclear whether the gut micro-biome contributes directly to colitis-associated CRC in this model. The objective of this study was to determine whether dynamic fecal microbiota transfer (FMT) from host mice fed either AIN or TWD basal diets would alter colitis symptoms or colitis-associated CRC in recipient mice, which were fed either AIN or TWD directly using a 2x2 factorial experiment …


Characterizing The Range Shifts Of Two Peromyscus Species In Maine, Molly Bennett May 2020

Characterizing The Range Shifts Of Two Peromyscus Species In Maine, Molly Bennett

Honors College

In a changing climate, two species of mice in Maine (Peromyscus maniculatus and Peromyscus leucopus) are currently undergoing range shifts. The objective of my thesis is to determine the historical and current range of each species within the state of Maine. I used two approaches. I assembled ear biopsies collected this summer in Acadia National Park and throughout the state by the Gardner and Levesque labs to genotype the mice as either P. maniculatus or P. leucopus. Additionally, I summarized research that denotes where the two species were historically present around the state. These species are functionally impossible to tell …


Granulosa Cell Proliferation Is Inhibited By Pge2 In The Primate Ovulatory Follicle, Patric S. Lundberg, Gil J. Moskowitz, Carmel Bellacose, Esra Demirel, Heidi A. Trau, Diane M. Duffy Jan 2020

Granulosa Cell Proliferation Is Inhibited By Pge2 In The Primate Ovulatory Follicle, Patric S. Lundberg, Gil J. Moskowitz, Carmel Bellacose, Esra Demirel, Heidi A. Trau, Diane M. Duffy

Computer Science Faculty Publications

Prostaglandin E2 (PGE2) is a key paracrine mediator of ovulation. Few specific PGE2-regulated gene products have been identified, so we hypothesized that PGE2 may regulate the expression and/or activity of a network of proteins to promote ovulation. To test this concept, Ingenuity Pathway Analysis (IPA) was used to predict PGE2-regulated functionalities in the primate ovulatory follicle. Cynomolgus macaques underwent ovarian stimulation. Follicular granulosa cells were obtained before (0 h) or 36 h after an ovulatory dose of human chorionic gonadotropin (hCG), with ovulation anticipated 37-40 h after hCG. Granulosa cells were obtained from additional monkeys 36 h after treatment with …


Germ Cell-Depleted Ovaries Improve Metabolic Health In Post-Reproductive Mice, Kyleigh Tyler Mar 2019

Germ Cell-Depleted Ovaries Improve Metabolic Health In Post-Reproductive Mice, Kyleigh Tyler

Research on Capitol Hill

Reproductive senescence is correlated with many deleterious heath conditions. In human females, the decline of health associated with reproductive function is termed “menopause.“ One of the declining health factors is metabolism.

In order to understand how ovaries contribute to metabolic health, we further studied the structure of ovaries. Within ovaries, there are two main types of cells:

  • Germ Cells (oocyte): Play a central role in reproduction (egg)
  • Somatic Cells: Supporting cells for germ cells

This study aimed to understand the relationship between germ cells and somatic cells and how this relationship influenced metabolism.


Small-Animal Models Of Zika Virus, Justin G. Julander, Venkatraman Siddharthan Dec 2017

Small-Animal Models Of Zika Virus, Justin G. Julander, Venkatraman Siddharthan

Animal, Dairy, and Veterinary Science Faculty Publications

Zika virus (ZIKV) infection can result in serious consequences, including severe congenital manifestations, persistent infection in the testes and neurologic sequelae. After a pandemic emergence, the virus has spread to much of the new world and has been introduced to many countries outside of endemic areas as infected travelers return to their home countries. Rodent models have been important in gaining a better understanding of the wide range of disease etiologies associated with ZIKV infection and for the initial phase of developing countermeasures to prevent or treat viral infections. We discuss herein the advantages and disadvantages of small animal models …


Estrogen Receptor Alpha (Esr1)-Dependent Regulation Of The Mouse Oviductal Transcriptome, Katheryn L. Cerny, Rosanne A. C. Ribeiro, Myoungkun Jeoung, Chemyong Ko, Phillip J. Bridges Jan 2016

Estrogen Receptor Alpha (Esr1)-Dependent Regulation Of The Mouse Oviductal Transcriptome, Katheryn L. Cerny, Rosanne A. C. Ribeiro, Myoungkun Jeoung, Chemyong Ko, Phillip J. Bridges

Animal and Food Sciences Faculty Publications

Estrogen receptor-α (ESR1) is an important transcriptional regulator in the mammalian oviduct, however ESR1-dependent regulation of the transcriptome of this organ is not well defined, especially at the genomic level. The objective of this study was therefore to investigate estradiol- and ESR1-dependent regulation of the transcriptome of the oviduct using transgenic mice, both with (ESR1KO) and without (wild-type, WT) a global deletion of ESR1. Oviducts were collected from ESR1KO and WT littermates at 23 days of age, or ESR1KO and WT mice were treated with 5 IU PMSG to stimulate follicular development and the production of ovarian estradiol, and the …


Lifecycle Efficiency Of Mice Divergently Selected For Heat Loss, Adrienne Bhatnagar May 2014

Lifecycle Efficiency Of Mice Divergently Selected For Heat Loss, Adrienne Bhatnagar

Department of Animal Science: Dissertations, Theses, and Student Research

Divergent selection for heat loss as an indication of maintenance energy requirements in mice resulted in a low (ML) and high maintenance line (MH), and an intermediate control line (MC). Improved feed efficiency has been observed in ML mice, which would be economically beneficial in livestock species. However, previous work showed evidence of unfavorable correlated responses to selection in ML mice compared to MH mice. Therefore, the objective of this study was to model a lifecycle similar to a livestock production system using these lines and determine if these correlated responses diminish the benefit of improved feed efficiency by calculating …


Bioengineered Lysozyme Reduces Bacterial Burden And Inflammation In A Murine Model Of Mucoid Pseudomonas Aeruginosa Lung Infection, Charlotte C. Teneback, Thomas C. Scanlon, Matthew J. Wargo, Jenna L. Bement, Karl E. Griswold, Laurie W. Leclair Aug 2013

Bioengineered Lysozyme Reduces Bacterial Burden And Inflammation In A Murine Model Of Mucoid Pseudomonas Aeruginosa Lung Infection, Charlotte C. Teneback, Thomas C. Scanlon, Matthew J. Wargo, Jenna L. Bement, Karl E. Griswold, Laurie W. Leclair

Dartmouth Scholarship

The spread of drug-resistant bacterial pathogens is a growing global concern and has prompted an effort to explore potential adjuvant and alternative therapies derived from nature's repertoire of bactericidal proteins and peptides. In humans, the airway surface liquid layer is a rich source of antibiotics, and lysozyme represents one of the most abundant and effective antimicrobial components of airway secretions. Human lysozyme is active against both Gram-positive and Gram-negative bacteria, ac


Renewed Selection For Heat Loss In Mice: Direct Responses And Correlated Responses In Feed Intake, Body Weight, Litter Size, And Conception Rate, J. M. Mcdonald, Merlyn K. Nielsen Jan 2007

Renewed Selection For Heat Loss In Mice: Direct Responses And Correlated Responses In Feed Intake, Body Weight, Litter Size, And Conception Rate, J. M. Mcdonald, Merlyn K. Nielsen

Department of Animal Science: Faculty Publications

Divergent selection in mice was renewed in 3 independent replicates for high (MH) and low (ML) heat loss. An unselected control (MC) was maintained in all replicates. Heat loss was measured for individual male mice for 15 h, overnight in direct calorimeters. After 16 initial generations of selection followed by 26 generations of relaxed selection, divergent selection resumed for 9 generations. The realized selection applied was very close to the maximum possible selection according to the criteria and protocol. Selection differentials were greater for high than for low selection due to greater variation in the MH line. When corrected for …


Measuring Ultrasonic Communication Between Mouse Pups And Adult Mother Mice, Katie Ludwig Jan 2007

Measuring Ultrasonic Communication Between Mouse Pups And Adult Mother Mice, Katie Ludwig

Undergraduate Research Symposium (UGRS)

Measuring ultrasonic communication provides us with a way to study parental influence on animals. In this study I measured the ultrasonic communication between mouse pups and two maternal females, one of which who had given birth to the pups and the other had raised them. I found that there was no significant difference between the amount of noise expressed by pups in response to each the biological mother and foster mother test groups. Mouse pups call to maternal females regardless of genetic relatedness. Communication in mice may be a more complicated model because of their communal nature.


Comparison Of Feed Energy Costs Of Maintenance, Lean Deposition, And Fat Deposition In Three Lines Of Mice Selected For Heat Loss, D. L. Eggert, Merlyn K. Nielsen Jan 2006

Comparison Of Feed Energy Costs Of Maintenance, Lean Deposition, And Fat Deposition In Three Lines Of Mice Selected For Heat Loss, D. L. Eggert, Merlyn K. Nielsen

Department of Animal Science: Faculty Publications

Three replications of mouse selection populations for high heat loss (MH), low heat loss (ML), and a nonselected control (MC) were used to estimate the feed energy costs of maintenance and gain and to test whether selection had changed these costs. At 21 and 49 d of age, mice were weighed and subjected to dual x-ray densitometry measurement for prediction of body composition. At 21 d, mice were randomly assigned to an ad libitum, an 80% of ad libitum, or a 60% of ad libitum feeding group for 28-d collection of individual feed intake. Data were analyzed using 3 approaches. …


Evaluation Of Immunomodulators, Interferons And Known In Vitro Sars-Cov Inhibitors For Inhibition Of Sars-Cov Replication In Balb/C Mice, Dale L. Barnard, C. W. Day, K. Bailey, M. Heiner, R. Montgomery, L. Lauridsen, P. K-S. Chan, R. W. Sidwell Jan 2006

Evaluation Of Immunomodulators, Interferons And Known In Vitro Sars-Cov Inhibitors For Inhibition Of Sars-Cov Replication In Balb/C Mice, Dale L. Barnard, C. W. Day, K. Bailey, M. Heiner, R. Montgomery, L. Lauridsen, P. K-S. Chan, R. W. Sidwell

Animal, Dairy, and Veterinary Science Faculty Publications

Compounds approved for therapeutic use and in vitro inhibitors of severe acute respiratory syndrome coronavirus (SARS-CoV) were evaluated for inhibition in the mouse SARS-CoV replication model. A hybrid interferon, interferon alpha (IFN-alpha) B/D, and a mismatched double-stranded (ds) RNA interferon (IFN) inducer, Ampligen® (poly I:poly C124), were the only compounds that potently inhibited virus titres in the lungs of infected mice as assessed by CPE titration assays. When mice were dosed intraperitoneally (i.p.) with IFN-alpha B/D once daily for 3 days beginning 4 h after virus exposure, SARS-CoV replication in the lungs of infected mice was reduced by 1 log10 …


Performance Of Mouse Lines Divergently Selected For Heat Loss When Exposed To Different Environmental Temperatures. I. Reproductive Performance, Pup Survival, And Metabolic Hormones, P. M. Kgwatalala, J. L. Deroin, Merlyn K. Nielsen Jan 2004

Performance Of Mouse Lines Divergently Selected For Heat Loss When Exposed To Different Environmental Temperatures. I. Reproductive Performance, Pup Survival, And Metabolic Hormones, P. M. Kgwatalala, J. L. Deroin, Merlyn K. Nielsen

Department of Animal Science: Faculty Publications

Mouse populations differing in metabolic rate have been developed through selection for high (MH) and low (ML) heat loss, along with the unselected controls (MC). Objectives of the study were to compare the MH, ML, and MC lines for reproductive performance, pup survival, and metabolic hormones when reared at 12, 22, and 31°C, and to search for line × environment interactions. Conception and litter size were recorded on the parent generation mice introduced to the environments at 11 wk of age and bred after a 3-wk acclimatization period. Survival of pups (pre-weaning to 3 wk; post-weaning from 3 to 9 …


Topical Cidofovir Is More Effective Than Is Parenteral Therapy For Treatment Of Progressive Vaccinia In Immunocompromised Mice, Donald F. Smee, K. W. Bailey, M-H. Wong, M. K. Wandersee, R. W. Sidwell Jan 2004

Topical Cidofovir Is More Effective Than Is Parenteral Therapy For Treatment Of Progressive Vaccinia In Immunocompromised Mice, Donald F. Smee, K. W. Bailey, M-H. Wong, M. K. Wandersee, R. W. Sidwell

Animal, Dairy, and Veterinary Science Faculty Publications

Background.Severe complications may arise as a result of virus dissemination after smallpox (live vaccinia virus) vaccination, particularly in immunocompromised individuals. We developed a new mouse model for studying the effects of antiviral agents on progressive vaccinia virus infections.

Methods.Hairless mice were treated with cyclophosphamide (100 mg/kg/day) every 4 days starting 1 day before vaccinia virus exposure to wounded skin. Primary lesions progressed in severity, satellite lesions developed, and the infection eventually killed the mice.

Results.Topical treatment with 1%‐cidofovir cream (twice daily for 7 days) was much more effective in reducing the severity of primary lesions and the number of satellite …


Performance Of Mouse Lines Divergently Selected For Heat Loss When Exposed To Different Environmental Temperatures. Ii. Feed Intake, Growth, Fatness, And Body Organs, P. M. Kgwatalala, Merlyn K. Nielsen Jan 2004

Performance Of Mouse Lines Divergently Selected For Heat Loss When Exposed To Different Environmental Temperatures. Ii. Feed Intake, Growth, Fatness, And Body Organs, P. M. Kgwatalala, Merlyn K. Nielsen

Department of Animal Science: Faculty Publications

Mouse populations differing in metabolic rate have been developed through selection for high (MH) and low (ML) heat loss, along with the unselected controls (MC). Objectives of the study were to compare the MH, ML, and MC lines for feed intake, growth, body fatness, and organ weights when reared at 12, 22, and 31°C, and investigate potential line × environment interactions. Feed intake was recorded weekly from 3 to 9 wk of age, and BW at 3, 6, and 9 wk of age. Body fat percent and organ weights were measured at 9 wk of age. No line × environment …


Selection For Maternal Behavior In Mice—Direct And Correlated Responses, Chung-Feng Chiang, Rodger K. Johnson, Merlyn K. Nielsen Dec 2002

Selection For Maternal Behavior In Mice—Direct And Correlated Responses, Chung-Feng Chiang, Rodger K. Johnson, Merlyn K. Nielsen

Department of Animal Science: Faculty Publications

Three generations of divergent selection for a maternal care index (MCI) in mice were practiced in each of three replicates. MCI was recorded for 29–32 dams and litters in each replicate/line subclass. Pups of the top (or bottom) 6– 10 dams in each replicate, depending on number of females in the litters, were selected in high (H) and low (L) MCI lines. At birth, litters with more than 10 pups were standardized to 10 pups whereas litters with no more than 10 pups remained intact. On day 4, 8, 12, and 16 of lactation, time budgets during a 30-min session …


Maternal Behavior In Mice Selected For Large Litter Size, Chung-Feng Chiang, Rodger . K. Johnson, Merlyn K. Nielsen Sep 2002

Maternal Behavior In Mice Selected For Large Litter Size, Chung-Feng Chiang, Rodger . K. Johnson, Merlyn K. Nielsen

Department of Animal Science: Faculty Publications

A total of 96 lactating mice and their pups from each of three replications of lines selected 21 generations for increased litter size (LS) followed by 23–25 generations of random selection and contemporary unselected control lines (LC) were characterized for maternal behavior. Sixteen dams and their pups from each replication of LS and LC lines were sampled. Litter sizes at birth for LS versus LC in the first, second, and third replicates were 17.3 versus 13.2, 15.9 versus 13.1, and 12.3 versus 10.6 pups, respectively, with LS dams averaging 2.87 ± .70 pups more. One-half of the litters were standardized …


A Simulation Model Including Ovulation Rate, Potential Embryonic Viability, And Uterine Capacity To Explain Litter Size In Mice: Ii. Responses To Alternative Criteria Of Selection, E. L. De A. Ribeiro, Merlyn K. Nielsen, Kreg A. Leymaster, Gary Bennett Jan 1997

A Simulation Model Including Ovulation Rate, Potential Embryonic Viability, And Uterine Capacity To Explain Litter Size In Mice: Ii. Responses To Alternative Criteria Of Selection, E. L. De A. Ribeiro, Merlyn K. Nielsen, Kreg A. Leymaster, Gary Bennett

Department of Animal Science: Faculty Publications

Direct selection for litter size was compared with selection for ovulation rate, ova success, or uterine capacity and for indexes of ovulation rate with ova success or uterine capacity. Selection was simulated for 10 generations in a mouse population based on a model integrating ovulation rate, potential embryonic viability, and uterine capacity. Two indexes including ovulation rate (OR) and ova success (OS) were I = .291 x OR + 2.19 x OS and I = .165 x OR + .736 x OS. Heritabilities for ovulation rate and ova success, assumed in the simulation and to derive the indexes, were .25 …


A Simulation Model Including Ovulation Rate, Potential Embryonic Viability, And Uterine Capacity To Explain Litter Size In Mice: I. Model Development And Implementation, E. L. De A. Ribeiro, Merlyn K. Nielsen, Gary Bennett, Kreg A. Leymaster Jan 1997

A Simulation Model Including Ovulation Rate, Potential Embryonic Viability, And Uterine Capacity To Explain Litter Size In Mice: I. Model Development And Implementation, E. L. De A. Ribeiro, Merlyn K. Nielsen, Gary Bennett, Kreg A. Leymaster

Department of Animal Science: Faculty Publications

Litter size in mice was studied using a model including ovulation rate, potential embryonic viability, and uterine capacity. Simulated results were compared with experimental results from a selection experiment with mice. The four criteria of selection were selection on number born (LS), selection on an index of ovulation rate and ova success (IX), selection on number born to unilaterally ovariectomized females (UT), and unselected control (LC). Comparisons were made to statistics of the base generation and to responses after 13 generations of selection. Phenotypic and genetic statistics for uterine capacity were generated so that simulations produced the experimental means, standard …


Divergent Selection For Heat Loss In Mice: I. Selection Applied And Direct Response Through Fifteen Generations, Merlyn K. Nielsen, L. D. Jones, B. A. Freking, J. A. Deshazer Jan 1997

Divergent Selection For Heat Loss In Mice: I. Selection Applied And Direct Response Through Fifteen Generations, Merlyn K. Nielsen, L. D. Jones, B. A. Freking, J. A. Deshazer

Department of Animal Science: Faculty Publications

Divergent selection for heat production/ loss (kcal•kg-.75•d-1) , measured in 9- to 11-wk-old male mice, was conducted for 15 generations. Heat loss was measured for 15 h on individual animals placed overnight in direct, gradient-layer calorimeters. Selection for high (MH) and low (ML) heat loss and unselected control (MC) occurred in each of three replicates for a total of nine unique lines. Repeatability of the heat loss measurement was .45 and the CV was 10.5%. Cumulative realized selection differentials, averaged for the three replicates, were 145.1 and -105.0 (kcal•kg-.75•d-1) and ranged from …


Divergent Selection For Heat Loss In Mice: Ii. Correlated Responses In Feed Intake, Body Mass, Body Composition, And Number Born Through Fifteen Generations, Merlyn K. Nielsen, B. A. Freking, L. D. Jones, S. M. Nelson, T. L. Vorderstrasse, B. A. Hussey Jan 1997

Divergent Selection For Heat Loss In Mice: Ii. Correlated Responses In Feed Intake, Body Mass, Body Composition, And Number Born Through Fifteen Generations, Merlyn K. Nielsen, B. A. Freking, L. D. Jones, S. M. Nelson, T. L. Vorderstrasse, B. A. Hussey

Department of Animal Science: Faculty Publications

Divergent selection for heat loss (kcal•kg-.75•d-1) , measured in 9- to 11-wk-old male mice, was conducted for 15 generations. Selection for high (MH) and low (ML) heat loss and unselected control (MC) occurred in each of three replicates for a total of nine unique lines. Feed intake in males was measured during Generations 9 through 15. Body mass at commencement of mating in females and at time of measurement of heat loss in males was recorded. Body fat percentage at 12 wk for animals of Generations 6, 10, and 14 was predicted as a function of …


Embryonal Survival To 6 Days In Mice Selected On Different Criteria For Litter Size, E. L. De A. Ribeiro, M. A. J. Van Engelen, Merlyn K. Nielsen Jan 1996

Embryonal Survival To 6 Days In Mice Selected On Different Criteria For Litter Size, E. L. De A. Ribeiro, M. A. J. Van Engelen, Merlyn K. Nielsen

Department of Animal Science: Faculty Publications

Embryonal survival was compared in mice resulting from four criteria of selection: LS = selection on number born; IX = selection on an index of ovulation rate and ova success; UT = selection on number born to unilaterally ovariectomized females; and LC = unselected control. Selection occurred for 21 generations with three replicates of the four criteria; thereafter, relaxed selection was practiced. The evaluation was performed using mice of two replicates at Generation 35 and one replicate at Generation 36. Data on a total of 289 female mice were recorded. Females, at an average age of 9 wk, were mated …


Estimates Of Heritabilities And Genetic And Environmental Correlations For Left- And Right-Side Uterine Capacity And Ovulation Rate In Mice, Merlyn K. Nielsen, Y. L. Kochera Kirby, A. C. Clutter Jan 1996

Estimates Of Heritabilities And Genetic And Environmental Correlations For Left- And Right-Side Uterine Capacity And Ovulation Rate In Mice, Merlyn K. Nielsen, Y. L. Kochera Kirby, A. C. Clutter

Department of Animal Science: Faculty Publications

Heritabilities for and genetic and environmental correlations between uterine capacity, ovulation rate, and body mass (BM) were estimated in mice. Uterine capacity was defined as the number of fetuses (LUC or RUC for left or right side) in one uterine horn for unilaterally ovariectomized females. Ovulation rate (corpora lutea, LCL or RCL for left or right ovary) was measured on the remaining single ovary in these same females. Data on 1,931 mice from four selection populations were used. Left ovulation rate and LUC were measured on 958 animals, and RCL and RUC of another 972 animals were recorded. Genetic and …


Uterine Mass And Uterine Blood Volume In Mice Selected 21 Generations For Alternative Criteria To Increase Litter Size, Merlyn K. Nielsen, R. J. Kittok, Y. L. Kochera Kirby Jan 1995

Uterine Mass And Uterine Blood Volume In Mice Selected 21 Generations For Alternative Criteria To Increase Litter Size, Merlyn K. Nielsen, R. J. Kittok, Y. L. Kochera Kirby

Department of Animal Science: Faculty Publications

Lines of mice, selected for 21 generations using alternative criteria to increase litter size, were evaluated for uterine mass and uterine blood volume to help explain differences in uterine capacity. For this study, mice were sampled from Generation 27, the sixth generation after relaxation of selection. Mice came from all four criteria of selection (LS = selection on number born to unaltered females; M = selection on an index of ovulation rate and ova success; UT = selection on uterine capacity; and LC = unselected control) in each of three replicates (a total of 12 lines). Measurement was at one …


Differences In Pup Birth Weight, Pup Variability Within Litters, And Dam Weight Of Mice Selected For Alternative Criteria To Increase Litter Size, M. A. J/ Van Engelen, Merlyn K. Nielsen, E. L. De A. Ribeiro Jan 1995

Differences In Pup Birth Weight, Pup Variability Within Litters, And Dam Weight Of Mice Selected For Alternative Criteria To Increase Litter Size, M. A. J/ Van Engelen, Merlyn K. Nielsen, E. L. De A. Ribeiro

Department of Animal Science: Faculty Publications

Selection for litter size had been practiced for 21 generations and relaxed selection for 13 generations in mice. Three replicates were used with four selection criteria: index of components (ovulation rate and ova success), uterine capacity, litter size, and an unselected control. Especially with selection for litter size and the index relative to the control, number of pups born had increased, and differences also occurred in mating weight. Dams of the three replicates and their litters were used to evaluate the effects of accumulated selection on pup birth weight, variability in weight of littermates, and dam's weight at mating and …


Uterine Capacity And Ovulation Rate In Mice Selected 21 Generations On Alternative Criteria To Increase Litter Size, A. C. Clutter, Y. Kochera Kirby, Merlyn K. Nielsen Jan 1994

Uterine Capacity And Ovulation Rate In Mice Selected 21 Generations On Alternative Criteria To Increase Litter Size, A. C. Clutter, Y. Kochera Kirby, Merlyn K. Nielsen

Department of Animal Science: Faculty Publications

After 21 generations of selection for alternative criteria to change litter size in mice, responses in uterine capacity and ovulation rate were evaluated. Females from Generations 22 and 23 were sampled from 12 lines, representing three replicates of four selection criteria: LS = direct selection on litter size; M = selection on an index of ovulation rate and the proportion of ova shed that resulted in fully formed offspring; UT = selection on uterine capacity measured as litter size from females unilaterally ovariectomized at 4 wk of age; and LC = unselected control. All females in the present evaluation (a …


Alternative Methods Of Selection For Litter Size In Mice: Iii. Response To 21 Generations Of Selection, Yvonne Kochera Kirby, Merlyn K. Nielsen Jan 1993

Alternative Methods Of Selection For Litter Size In Mice: Iii. Response To 21 Generations Of Selection, Yvonne Kochera Kirby, Merlyn K. Nielsen

Department of Animal Science: Faculty Publications

Alternative methods of selection to increase litter size in mice have been practiced for 21 generations followed by six generations of relaxed selection. Three replicates were used with four selection criteria: index of components (IX: I = 1.21 x total ovulation rate + 9.05 x ova success), uterine capacity (UT), litter size (LS), and an unselected control (LC). In IX, ovulation rate and ova success were measured by number of corpora lutea and number of pups born/number of corpora lutea, respectively. In UT, uterine capacity was measured and defined as number of pups born to unilaterally ovariectomized (right ovary excised) …


Genetic Variation Liver Mass, Body Mass, And Liver:Body Mass In Mice, L. D. Jones, Merlyn K. Nielsen, R. Britton Jan 1992

Genetic Variation Liver Mass, Body Mass, And Liver:Body Mass In Mice, L. D. Jones, Merlyn K. Nielsen, R. Britton

Department of Animal Science: Faculty Publications

Genetic variation for liver mass (LM), body mass (BM), and 1iver:body mass (LM/ BM) was examined for outbred populations of laboratory mice. Liver mass and body mass data were collected on 170 pureline sires at 12 wk of age, representing four outbred stocks of laboratory mice; 523 of their male and female two-way cross progeny at 9 or 12 wk; and 214 four-way-cross' offspring at 12, 14, or 16 wk. Genetic differences for LM, BM, and LM/BM were found among the base sire lines and between two-way crosses. Heritabilities and genetic correlations for LM, BM, LM/BM, and LM/MBM (MBM = …


Alternative Methods Of Selection For Litter Size In Mice: I. Characterization Of Base Population And Development Of Methods, A. C. Clutter, Merlyn K. Nielsen, R. K. Johnson Nov 1990

Alternative Methods Of Selection For Litter Size In Mice: I. Characterization Of Base Population And Development Of Methods, A. C. Clutter, Merlyn K. Nielsen, R. K. Johnson

Department of Animal Science: Faculty Publications

Studies on a base population of mice were used to establish an index of components of litter size and a physiological model for measuring uterine capacity to be used subsequently in a selection experiment evaluating alternative methods for practicing selection to increase litter size. Heritability estimates of litter size, ovulation rate and ova success (fraction of ova resulting in fully formed pups) were .18, .33 and .15, respectively. No significant genetic or phenotypic correlation was found between overall ovulation rate and ova success. Phenotypic means and genetic variances were higher for characteristics measured on the right than on the left …