Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 20 of 20
Full-Text Articles in Genetics and Genomics
An Rnai-Based Suppressor Screen Identifies Interactors Of The Myt1 Ortholog Of Caenorhabditis Elegans, Anna Allen, Jessica Nesmith, Andy Golden
An Rnai-Based Suppressor Screen Identifies Interactors Of The Myt1 Ortholog Of Caenorhabditis Elegans, Anna Allen, Jessica Nesmith, Andy Golden
Department of Biology Faculty Publications
Oocyte maturation in all species is controlled by a protein complex termed the maturation promoting factor (MPF). MPF is comprised of a cyclin-dependent kinase (CDK) and its partner cyclin, and is regulated by dueling regulatory phosphorylation events on the CDK. In Caenorhabditis elegans, the Wee1/Myt1 ortholog WEE-1.3 provides the inhibitory phosphorylations on CDK-1 that keep MPF inactive and halts meiosis. Prior work has shown that depletion of WEE-1.3 in C. elegans results in precocious oocyte maturation in vivo and a highly penetrant infertility phenotype. This study sought to further define the precocious maturation phenotype and to identify novel interactors with …
The Peopling Of The African Continent And The Diaspora Into The New World, Michael Campbell, Jibril Hirbo, Jeffrey Peter Townsend, Sarah Tishkoff
The Peopling Of The African Continent And The Diaspora Into The New World, Michael Campbell, Jibril Hirbo, Jeffrey Peter Townsend, Sarah Tishkoff
Department of Biology Faculty Publications
Africa is the birthplace of anatomically modern humans, and is the geographic origin of human migration across the globe within the last 100,000 years. The history of African populations has consisted of a number of demographic events that have influenced patterns of genetic and phenotypic variation across the continent. With the increasing amount of genomic data and corresponding developments in computational methods, researchers are able to explore long-standing evolutionary questions, expanding our understanding of human history within and outside of Africa. This review will summarize some of the recent findings regarding African demographic history, including the African Diaspora, and will …
Global Population-Specific Variation In Mirna Associated With Cancer Risk And Clinical Biomarkers, Renata Rawlings-Goss, Michael Campbell, Sarah Tishkoff
Global Population-Specific Variation In Mirna Associated With Cancer Risk And Clinical Biomarkers, Renata Rawlings-Goss, Michael Campbell, Sarah Tishkoff
Department of Biology Faculty Publications
Background: MiRNA expression profiling is being actively investigated as a clinical biomarker and diagnostic tool to detect multiple cancer types and stages as well as other complex diseases. Initial investigations, however, have not comprehensively taken into account genetic variability affecting miRNA expression and/or function in populations of different ethnic backgrounds. Therefore, more complete surveys of miRNA genetic variability are needed to assess global patterns of miRNA variation within and between diverse human populations and their effect on clinically relevant miRNA genes.
Gene-Environment Interactions In Human Health: Case Studies And Strategies For Developing New Paradigms And Research Methodologies, Fatimah Linda Collier Jackson
Gene-Environment Interactions In Human Health: Case Studies And Strategies For Developing New Paradigms And Research Methodologies, Fatimah Linda Collier Jackson
Department of Biology Faculty Publications
THE SYNERGISTIC EFFECTS OF GENES AND THE ENVIRONMENT ON HEALTH ARE EXPLORED IN THREE CASE STUDIES: adult lactase persistence, autism spectrum disorders, and the metabolic syndrome, providing examples of the interactive complexities underlying these phenotypes. Since the phenotypes are the initial targets of evolutionary processes, understanding the specific environmental contexts of the genetic, epigenetic, and environmental changes associated with these phenotypes is essential in predicting their health implications. Robust databases must be developed on the local scale to deconstruct both the population substructure and the unique components of the environment that stimulate geographically specific changes in gene expression patterns. To …
Limited Evidence For Adaptive Evolution And Functional Effect Of Allelic Variation At Rs702424 In The Promoter Of The Tas2r16 Bitter Taste Receptor Gene In Africa, Michael Campbell
Limited Evidence For Adaptive Evolution And Functional Effect Of Allelic Variation At Rs702424 In The Promoter Of The Tas2r16 Bitter Taste Receptor Gene In Africa, Michael Campbell
Department of Biology Faculty Publications
Bitter taste perception, mediated by receptors encoded by the TAS2R loci, has important roles in human health and nutrition. Prior studies have demonstrated that nonsynonymous variation at site 516 in the coding exon of TAS2R16, a bitter taste receptor gene on chromosome 7, has been subject to positive selection and is strongly correlated with differences in sensitivity to salicin, a bitter anti-inflammatory compound, in human populations. However, a recent study suggested that the derived G-allele at rs702424 in the TAS2R16 promoter has also been the target of recent selection and may have an additional effect on the levels of salicin …
Genetic Origins Of Lactase Persistence And The Spread Of Pastoralism In Africa, Michael Campbell
Genetic Origins Of Lactase Persistence And The Spread Of Pastoralism In Africa, Michael Campbell
Department of Biology Faculty Publications
In humans, the ability to digest lactose, the sugar in milk, declines after weaning because of decreasing levels of the enzyme lactase-phlorizin hydrolase, encoded by LCT. However, some individuals maintain high enzyme amounts and are able to digest lactose into adulthood (i.e., they have the lactase-persistence [LP] trait). It is thought that selection has played a major role in maintaining this genetically determined phenotypic trait in different human populations that practice pastoralism. To identify variants associated with the LP trait and to study its evolutionary history in Africa, we sequenced MCM6 introns 9 and 13 and ∼2 kb of the …
Frequency-Dependent Mate Selection In The Guppy (Poeciliidae: Poecilia Reticulata), Andre Porter, Jack Frankel
Frequency-Dependent Mate Selection In The Guppy (Poeciliidae: Poecilia Reticulata), Andre Porter, Jack Frankel
Department of Biology Faculty Publications
Heterogeneity within a population enhances its long-term survival. A fundamental method of maintaining population heterogeneity is the retention of rare or uncommon phenotypes by selective mating strategies. Employing two color morphs, red tuxedo and red, of the guppy (Poecilia reticulata, Poeciliidae), this study was designed to investigate whether P. reticulata females would preferentially seek out heterogeneous groupings of males exhibiting two color morphs. Adult female guppies were exposed simultaneously to two groups of males (n=10); one comprised of only the tuxedo color morph (n=5) and the other of both color morphs (n=5). For the latter group, the ratio of males …
Inheritance Of Humeral Spotting In The Croaking Gourami (Osphronemidae: Trichopsis Vittatus), Jack Frankel, Lisa Alder-Golden, Andre Porter
Inheritance Of Humeral Spotting In The Croaking Gourami (Osphronemidae: Trichopsis Vittatus), Jack Frankel, Lisa Alder-Golden, Andre Porter
Department of Biology Faculty Publications
The croaking gourami (Trichopsis vittatus) exhibits two phenotypes associated with humeral spotting. Fish possess a prominent, dark humeral patch or spot located behind the operculum or lack this spotting pattern. Segregation patterns observed from the progenies of eleven different crosses support the hypothesis that the inheritance of humeral spotting in T. vittatus is controlled by the action of a single autosomal locus, with complete dominance of the allele controlling the spotted phenotype.
Emb-1 Encodes The Apc16 Subunit Of The Caenorhabditis Elegans Anaphase-Promoting Complex, Diane Shakes, Anna Allen, Kelsey Albert, Andy Golden
Emb-1 Encodes The Apc16 Subunit Of The Caenorhabditis Elegans Anaphase-Promoting Complex, Diane Shakes, Anna Allen, Kelsey Albert, Andy Golden
Department of Biology Faculty Publications
In the nematode Caenorhabditis elegans, temperature-sensitive mutants of emb-1 arrest as one-cell embryos in metaphase of meiosis I in a manner that is indistinguishable from embryos that have been depleted of known subunits of the anaphase-promoting complex or cyclosome (APC/C). Here we show that the emb-1 phenotype is enhanced in double mutant combinations with known APC/C subunits and suppressed in double mutant combinations with known APC/C suppressors. In addition to its meiotic function, emb-1 is required for mitotic proliferation of the germline. These studies reveal that emb-1 encodes K10D2.4, a homolog of the small, recently discovered APC/C subunit, APC16.
Genomic Variation And Adaptation In Africa: Implications For Human Evolutionary History And Disease, Michael Campbell
Genomic Variation And Adaptation In Africa: Implications For Human Evolutionary History And Disease, Michael Campbell
Department of Biology Faculty Publications
Africa contains the greatest levels of human genetic variation and is the source of the worldwide range expansion of all modern humans. However, relatively little is known about genomic variation in ethnically diverse African populations.
Inheritance Of Shoulder Spotting In The Tetra, Hyphessobrycon Bentosi Characidae, Jack Frankel
Inheritance Of Shoulder Spotting In The Tetra, Hyphessobrycon Bentosi Characidae, Jack Frankel
Department of Biology Faculty Publications
The tetra (Hyphessobrycon bentosi) exhibits two phenotypes associated with shoulder spotting. Fish possess ei-ther a prominent black vertical spot located directly behind the operculum (H. b. bentosi, bentosi white tip tetra) or lack this spot (H. b. rosaceus, rosy tetra). Segregation patterns observed from the progenies of ten different crosses suggest that the inheritance of these phenotypes is controlled by two autosomal loci acting in a complementary fashion, with domi-nance at both loci required for the expression of the spotted phenotype.
Monogenic Control Of Sex-Limited Colouration In The Honey Gourami, Trichogaster Chuna, Jack Frankel
Monogenic Control Of Sex-Limited Colouration In The Honey Gourami, Trichogaster Chuna, Jack Frankel
Department of Biology Faculty Publications
Of the numerous subtropical and tropical freshwater speciesof fish, labyrinth fish are among the most varied in bodymarkings and colouration patterns. Four taxonomic families(Belontiidae, Anabantidae, Helostomatidae, and Osphrone-midae) of the suborder Anabantoidei comprise the ‘tradi-tional’ labyrinth fishes, a group of about 80 African andSoutheast Asian species (Linke 1991). These Anabantoidsare popular with aquarists due to their interesting reproduc-tive behaviours, with males of most species brooding eggs intheir mouths or in floating bubble nests (Vevers 1980; Linke1991; Axelrod and Vorderwinkler 1995; Mills 2000). Theyhave also been the focus of genetic, environmental, and mor-phological studies (Sommer 1982; Gosline 1985; Klinkhardtet al. 1995; …
African Genetic Diversity: Implications For Human Demographic History, Modern Human Origins, And Complex Disease Mapping, Michael Campbell, Sarah Tishkoff
African Genetic Diversity: Implications For Human Demographic History, Modern Human Origins, And Complex Disease Mapping, Michael Campbell, Sarah Tishkoff
Department of Biology Faculty Publications
Comparative studies of ethnically diverse human populations, particularly in Africa, are important for reconstructing human evolutionary history and for understanding the genetic basis of phenotypic adaptation and complex disease. African populations are characterized by greater levels of genetic diversity, extensive population substructure, and less linkage disequilibrium (LD) among loci compared to non-African populations. Africans also possess a number of genetic adaptations that have evolved in response to diverse climates and diets, as well as exposure to infectious disease. This review summarizes patterns and the evolutionary origins of genetic diversity present in African populations, as well as their implications for the …
The Carnegie Protein Trap Library: A Versatile Tool For Drosophila Developmental Studies, Anna Allen
The Carnegie Protein Trap Library: A Versatile Tool For Drosophila Developmental Studies, Anna Allen
Department of Biology Faculty Publications
Metazoan physiology depends on intricate patterns of gene expression that remain poorly known. Using transposon mutagenesis in Drosophila, we constructed a library of 7404 protein trap and enhancer trap lines, the Carnegie collection, to facilitate gene expression mapping at single-cell resolution. By sequencing the genomic insertion sites, determining splicing patterns downstream of the enhanced green fluorescent protein (EGFP) exon, and analyzing expression patterns in the ovary and salivary gland, we found that 600-900 different genes are trapped in our collection. A core set of 244 lines trapped different identifiable protein isoforms, while insertions likely to act as GFP-enhancer traps were …
Digenic Control Of Colouration In The Two-Spot Gourami Trichogaster Trichopterus Trichopterus, Jack Frankel
Digenic Control Of Colouration In The Two-Spot Gourami Trichogaster Trichopterus Trichopterus, Jack Frankel
Department of Biology Faculty Publications
Labyrinth fishes of the families Anabantidae, Belontiidae,Helostomatidae, and Osphronemidae comprise the tradi-tional anabantoids, a group of about 80 relatively small African and southeast Asian species (Linke 1991). Many of the anabantoids are popular with aquarium hobbyists because of their interesting reproductive behaviours, with males of most species brooding eggs in their mouths or in floating bubble nests (Vevers 1980; Linke 1991; Axelrod and Vorderwinkler 1995; Mills 2000). They have also beenthe focus of several environmental, morphological, and gene-tic investigations (Sommer 1982; Gosline 1985; Waki-yama et al. 1997; Frankel 1992, 2001). The two-spot gourami, Trichogaster trichopterus trichopterus Pallas (Osphronemidae), is one …
Inheritance Of Trunk Banding In The Tetra (Gymnocorymbus Ternetzi Characidae), Jack Frankel
Inheritance Of Trunk Banding In The Tetra (Gymnocorymbus Ternetzi Characidae), Jack Frankel
Department of Biology Faculty Publications
The tetra (Gymnocorymbus ternetzi) exhibits two phenotypes associated with trunk banding. Fish possess either a smoky-gray coloration with two prominent black vertical bands located directly behind the operculum (black tetra) or a lighter coloration and lack these bands (white skirt tetra). Segregation patterns observed from the progenies of 11 different crosses suggest that the inheritance of these phenotypes is controlled by two autosomal loci acting in a complementary fashion, with dominance at both loci required for the expression of the darker, banded phenotype.
Human Genetic Variation And Health: New Assessment Approaches Based On Ethnogenetic Layering, Fatimah Linda Collier Jackson
Human Genetic Variation And Health: New Assessment Approaches Based On Ethnogenetic Layering, Fatimah Linda Collier Jackson
Department of Biology Faculty Publications
Human genetic variation is often biologically relevant, particularly when it influences (or is influenced by) health outcomes. For example, human genetic variation can modulate disease aetiology as in the case ofhomozygous beta sickle gene (βS/βS or sickle cell) pathology. Conversely, health outcomes, such as the frequency and duration of homozygous sickle cell pathology, can change affected group gene frequencies by selectively targeting and culling specific genotypes in a group, such as clinically more severe βS Bantu/βS Bantu versions of the βS gene, thereby changing future patterns of genetic variation in this gene.
Caudal Spotting In The Beacon Fish (Hemigrammus Ocellifer Characidae), Jack Frankel
Caudal Spotting In The Beacon Fish (Hemigrammus Ocellifer Characidae), Jack Frankel
Department of Biology Faculty Publications
The beacon fish (Hemigrammus ocellifer) exhibits two phenotypes associated with spotting at the base of the caudal fin, with fish either possessing (H. o. ocellifer) or lacking (H. o. falsus) a prominent red spot in this region. Segregation patterns observed from the progenies of 15 different crosses support a hypothesis that caudal spotting in this species is controlled by a single gene with two alleles, for which the caudal spotting allele is completely dominant.
Monogenic Control Of Iris Coloration In The January Tetra (Hemigrammus Hyanuary Characidae), Jack Frankel
Monogenic Control Of Iris Coloration In The January Tetra (Hemigrammus Hyanuary Characidae), Jack Frankel
Department of Biology Faculty Publications
The January tetra (Hemigrammus hyanuary Durbin) exhibits two eye color phenotypes. These have a silver iris, which is characteristic of the species, and a green color variant. Segregation patterns observed in the progenies from 12 different crosses support an hypothesis for the monogenic inheritance of iris coloration in this species.
Drosophila Alcohol Dehydrogenase: Developmental Studies On Cryptic Variant Lines, Gurbachan Miglani, Franklin Ampy
Drosophila Alcohol Dehydrogenase: Developmental Studies On Cryptic Variant Lines, Gurbachan Miglani, Franklin Ampy
Department of Biology Faculty Publications
Thirty-five cryptic variant lines were used to examine the mechanisms involved in genetic modulation of alcohol metabolism in Drosophila. Late third-instar larval, preemergence pupal, and adult stages cultured at 18 and 28 C were examined. Spectrophotometric analyses for native alcohol dehydrogenase (ADH) activity and residual ADH activity after treatment with guanidine hydrochloride and heat were performed. Differential response of cryptic variants to treatment with the denaturants during development suggested that this variation may have an adaptive significance.