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The Larvae Of Eurycea Junaluska (Amphibia: Caudata: Plethodontidae), With Comments On Distribution, Travis Ryan

Travis J. Ryan

Travis J. Ryan's shorter contribution to Copeia 1997.

Does Sex Influence Post-Reproductive Metamorphosis In Ambystoma Talpoideum?, Travis Ryan, Gabrielle Swenson

Travis J. Ryan

Shorter communication in the Journal of Herpetology v. 35.

Growth And The Expression Of Alternative Life Cycles In The Salamander Ambystoma Talpoideum (Caudata: Ambystomatidae), Travis Ryan, Raymond Semlitsch

Travis J. Ryan

Complex life cycles (CLCs) contain larval and adult phases that are morphologically and ecologically distinct. Simple life cycles (SLCs) have evolved from CLCs repeatedly in a wide variety of lineages but the processes that may underlie the transition have rarely been identified or investigated experimentally. We examined the influence of larval growth rate on the facultative expression of alternative life cycles (metamorphosis or maturation as gill-bearing adults [= paedomorphosis]) in the salamander Ambystoma talpoideum. We manipulated growth rates by altering the amount of food individuals received throughout larval development. The expression of alternative life cycles in A. talpoideum is influenced …

Evaporative Water Loss In Two Natricine Snakes, Nerodia Fasciata And Seminatrix Pygaea, Christopher Winne, Travis Ryan, Yale Leiden, Michael Dorcas

Travis J. Ryan

Shorter communication in Journal of Herpetology v. 35.

Aspects Of Sex-Specific Differences In The Expression Of An Alternative Life Cycle In The Salamander Ambystoma Talpoideum, Christopher Winne, Travis Ryan

Travis J. Ryan

A recent evolutionary ecological model of facultative paedomorphosis predicts that body size of mature individuals should be larger than immatures of the same cohort. We investigated sex-specific differences in body size and maturation within a single cohort of branchiate (= larval and paedomorphic) mole salamanders, Ambystoma talpoideum. In addition, we also sampled the population after the breeding season, as some individuals began to undergo metamorphosis and leave the pond. The branchiate population was female-biased (62.7%), and mature (paedomorphic) females were significantly smaller than paedomorphic males or immature (larval) females. The majority of male branchiates were mature (86.6%), whereas significantly fewer …

Geographic Distribution. Farancia Abacura., Kate Ingram, Travis Perry, Travis Ryan

Travis J. Ryan

Geographic distribution of the mud snake.

Ultrastructure Of The Reproductive System Of The Black Swamp Snake (Seminatrix Pygaea). I. Evidence For Oviducal Sperm Storage, David Sever, Travis Ryan

Travis J. Ryan

Oviducal sperm storage in the viviparous (lecithotrophic) colubrid snake Seminatrix pygaea was studied by light and electron microscopy. Out of 17 adult snakes examined from May–October, sperm were found in the oviducts of only two specimens. In a preovulatory female sacrificed 14 May, sperm were found in the oviducal lumen and sperm storage tubules (SSTs) of the posterior infundibulum. In a nonvitellogenic female sacrificed 9 June, sperm were found in the lumen and glands of the posterior uterus and anterior vagina, indicating a recent mating. The glands in the posterior infundibulum and vagina were simple or compound tubular, whereas glands …

Seminatrix Pygaea. Diet., Mark Mills, Travis Ryan, Sean Poppy, Anthony Mills, Michael Dorcas

Travis J. Ryan

Diet of black swamp snake.

Sex And Size Interaction And Standard Metabolic Rate Of Paedomorphic Ambystoma Talpoideum: Size Does Matter, Travis Ryan, William Hopkins

Travis J. Ryan

We measured the standard metabolic rate of paedomorphic Mole Salamanders (Ambystoma talpoideum) from South Carolina. Despite an absence of body size differences between females and males, analysis of covariance demonstrated metabolic rates (mL O2/h) were significantly influenced by an interaction between sex and body size. The interaction appeared as a result of changes in the size-metabolism relationship in males (a steeper slope in the size-metabolism regression in small males as compared to large males), whereas the relationship remained constant in females, regardless of size. We hypothesize that the observed differences are attributable to differences in reproductive physiology between the sexes. …

Larval Life History And Abundance Of A Rare Salamander, Eurycea Junaluska (Plethodontidae), Travis Ryan

Travis J. Ryan

The larval life history of Eurycea junaluska was studied in three southwestern North Carolina populations. Populations were sampled quarterly over a 13 mo period and size-class analyses were used to evaluate the pattern of larval growth and metamorphosis. Young of the year appeared in the late spring and experienced rapid growth through the first summer. Growth slowed in the second year and metamorphosis usually occured in the summer at about 25.5 mo post-hatching, although some data suggest that either 1yr or 3yr larval periods may be possible. The overall larval growth rate of E. junaluska is estimated at 1.27 mm/mo, …

The Evolution Of Billfish, Andrew Blitman

Andrew Blitman

No abstract provided.

Association Between Prostate Cancer In Black Americans And An Allele Of The Padprp Pseudogene Locus On Chromosome 13, Helen Donis-Keller, Jennifer Doll, B Suarez

Helen Donis-Keller

Black American men have a higher incidence of cancer of the prostate (CAP), multiple myeloma, and lung cancer than do white American men (discussed by Lyn et al.1993a). The basis for these differences no doubt includes environmental influences, because American blacks have also been found to have a higher incidence of CAP than do African blacks. However, genetic factors may play a role as well. For example, Lyn et al. (1993a) reported an increase in the frequency of an allele of the poly(ADPribose)polymerase (PADPRP) pseudogene locus onchromosome 13 in black Americans with CAP, suggesting the presence of a disease-susceptibility locus. …

Genetic Analysis Of Prostatic Atypical Adenomatous Hyperplasia (Adenosis), Helen Donis-Keller, Jennifer Doll, Xiaopei Zhu, Jaime Furman, Zahid Kaleem, Carlos Torres, Peter Humphrey

Helen Donis-Keller

Atypical adenomatous hyperplasia (AAH) of the prostate, a small glandular proliferation, is a putative precursor lesion to prostate cancer, in particular to the subset of well-differentiated carcinomas that arise in the transition zone, the same region where AAH lesions most often occur. Several morphological characteristics of AAH suggest a relationship to cancer; however, no definitive evidence has been reported. In this study, we analyzed DNA from 25 microdissected AAH lesions for allelic imbalance as compared to matched normal DNA, using one marker each from chromosome arms 1q, 6q, 7q, 10q, 13q, 16q, 17p, 17q, and 18q, and 19 markers from …

Sharks Of The Devonian, Andrew Blitman

Andrew Blitman

No abstract provided.

Mapping A Gene For Familial Hypertrophic Cardiomyopathy To Chromosome 14q1, John Jarcho, William Mckenna, J.A. Peter Pare, Scott Solomon, Randall Holcombe, Shaughan Dickie, Tatjana Levi, Helen Donis-Keller, J.G. Seidman, Christine Seidman

Helen Donis-Keller

To identify the chromosomal location of a gene responsible for familial hypertrophic cardiomyopathy, we used clinical and molecular genetic techniques to evaluate the members of a large kindred. Twenty surviving and 24 deceased family members had hypertrophic cardiomyopathy; 58 surviving members were unaffected. Genetic-linkage analyses were performed with polymorphic DNA loci dispersed throughout the entire genome, to identify a locus that was inherited with hypertrophic cardiomyopathy in family members. The significance of the linkage detected between the disease locus and polymorphic loci was assessed by calculating a lod score (the logarithm of the probability of observing coinheritance of two loci, …

Hydroperiod And Metamorphosis In The Small-Mouthed Salamander

Travis J. Ryan

Legacy Of Land Use In Southern Appalachian Forests: Effects On Terrestrial Salamander Abundance Along Edges And Within Abandoned Logging Roads, R. Semlitsch,, Travis Ryan, M. Chatfield, B. Drehman, K. Hamed, N. Pekarek, M. Spath

Travis J. Ryan

Presence And Colonization Of Placobdella On Two Species Of Freshwater Turtles (Graptemys Geographica And Sternotherus Odoratus), Travis Ryan

Travis J. Ryan

It is generally accepted that bottom-dwelling turtles have a higher ectoparasite load than turtles that bask aerially because of effects of desiccation on ectoparasites, especially with regard to leeches. We compared number of leeches (primarily Placobdella parasitica) on field-caught Common Musk Turtles (Stemotherus odoratus) and Common Map Turtles (Graptemys geographica). The bottom-dwelling species S. odoratus had more than 20 times the number of leeches than the aerial-basking species G. geographica. We then exposed cleaned (leech-free) turtles to leeches in mesocosms (cattle tanks) to measure the rate of colonization. In this experiment, S. odoratus had more than four times the number …

A Comprehensive Genetic Linkage Map Of The Human Genome, Nih/Ceph Collaborators Mapping Group, Helen Donis-Keller

Helen Donis-Keller

A genetic linkage map of the human genome was constructed that consists of 1416 loci, including 279 genes and expressed sequences. The loci are represented by 1676 polymorphic systems genotyped with the CEPH reference pedigree resource. A total of 339 microsatellite repeat markers assayed by PCR are contained within the map, and of the 351 markers with heterozygosities of at least 70%, 205 are microsatellites. Seven telomere loci define physical and genetic endpoints for 2q, 4p, 7q, 8p, 14q, 16p, and 16q, and in other cases distal markers on the maps have been localized to terminal cytogenetic bands. Therefore, at …

Rna Sequencing Provides Evidence For Allelism Of Determinants Of The N-, B-, Or Nb- Tropism Of Murine Leukemia Viruses, Jean Rommelaere, Helen Donis-Keller, Nancy Hopkins

Helen Donis-Keller

Previous genetic and biochemical studies identified three large RNAase T1-resistant oligonucleotides, each associated with either the N-, B- or NB-tropism of murine C-type viruses of BALB/c origin. These oligonucleotides were shown to lie in the 5′ third of the oligonucleotide maps of their respective viruses. We sequenced the three oligonucleotides and found that they share a 10 base sequence. Together these observations provide good evidence that the determinants of N-, B- or NB-tropism monitored by the three oligonucleotides are allelic.The oligonucleotides associated with N- and B-tropism differ in sequence at four of sixteen nucleotides, while the B- and NB-tropism-associated oligonucleotides …

Mapping Adenines, Guanines, And Pyrimidines In Rna, Helen Donis-Keller, Allan Maxam, Walter Gilbert

Helen Donis-Keller

The positions of adenines, guanines, and pyrimidines can be determined by partial nuclease digestion of a terminally labeled RNA molecule. In urea, at elevated temperatures, RNase T1 generates a pattern reflecting cleavage at guanines while RNase U2 cleaves only at adenine. A limited alkaline hydrolysis provides a continuum of fragments derived from breaks at every phosphodiester bond. The reaction products are electrophoretically fractionated by size in adjacent lanes of a polyacrylamide gel. An autoradiograph of the gel displays the sequence up to 100 nucleotides from the end of the molecule, although uracil cannot as yet be distinguished from cytosine. These …