Spelling suggestions: "subject:"polymorphism -"" "subject:"olymorphism -""
371 |
Mate Choice and Sexual Conflict in a Livebearing FishKasper, Julia C 01 August 2023 (has links) (PDF)
Eavesdropping occurs when a receiver extracts information from an interaction without directly engaging with the signaler. Eavesdropping has been shown to be an effective way of evaluating the quality of potential mates and their abilities in male-male competition, without having to directly interact with them, thereby reducing energy costs and mating harassment. Girardinus metallicus is a livebearing poeciliid fish endemic to Cuba whose mating system is dominated by mating harassment in the form of sneak copulations, persistent displaying, and male-male aggression. G. metallicus has a male specific polymorphism in both melanin coloration and behavior. Males with melanin coloration are known as black morphs. Black morph males show persistent displaying and higher aggression, whereas plain morph males, the most common morph, do not have pronounced melanin patches and mate solely by sneak copulation. Plain morph males exhibit lower levels of aggression than black morph males.
In Chapter 1, we created groups consisting of a female and two males differing in body size and exposed them to dichotomous choice tests of female preference before and after the females witnessed the males interacting with each other. We hypothesized that: 1) male morphological traits are sexually selected via female choice in G. metallicus because these traits indicate quality; 2) female G. metallicus eavesdrop on male aggression to make mate choice decisions because aggression may indicate the quality of the male and his propensity to harass females; and 3) male size classes differ in behavior and morphology (saturation, brightness, and gonopodium size), consistent with other poeciliid studies showing that body size influences phenotype and that these traits are intercorrelated. We predicted 1) females will associate more with more colorful males, males with shorter gonopodia, and the larger male, before eavesdropping on male-male interactions, after, or both; 2) females will spend more time associating with males that subsequently delivered more chases and bites to a competitor male; and 3) larger males would be more active, more persistent in mating attempts, be more aggressive, and have a larger gonopodium size, and greater saturation and brightness of their posterior, ventral, and dorsal body regions. We found that females prefer to associate with males whose body regions are highly saturated, before eavesdropping on the two males interacting, but females did not prefer saturation after eavesdropping. We also found that females had a preference for smaller gonopodia relative for a males’ body size after eavesdropping. We also found that as male size increases, gonopodium length is proportional to their standard length. This study is the first to show female preference for coloration traits within any morph of G. metallicus, suggesting that plain morph males are not as plain to females as their name suggests.
Individual animals consistently vary in the average level of behavior exhibited across a range of contexts, which is also known as personality. Behavioral syndromes are correlations among personalities grouping them together. Personality traits have implications for mate choice, fitness, and predator avoidance. In Chapter 2, we addressed behavioral traits and personality in females and whether they influence how males respond to different degrees of boldness, activity, and aggression. We assessed female latency time to emerge from a refuge chamber, activity level, and aggressiveness to another female, on three successive days. We then quantified the degree of mating harassment each female experienced, when tested with a male. We hypothesized the following: 1) female G. metallicus exhibit personality across behavioral contexts (risk, activity, and resource competition), consistent with findings in other poeciliids including male G. metallicus; 2) the rank orders of boldness, activity, and aggression are positively correlated, consistent with other poeciliid studies that found evidence for behavioral syndromes; and 3) female personality traits mitigate male harassment because females that exhibit those personality traits are better at avoiding/retaliating against male harassment. We predicted that: 1) behavioral traits (latency time to emerge, boxes entered, and chases, bites, and fin flares delivered to a female competitor) measured within each context would be repeatable; 2) female rank orders of boldness, activity, and aggression personalities would be positively correlated with each other; 3) that larger females would experience less harassment; and 4) when females directly interact with a male, females that are bolder, more active, and more aggressive (bites and chases delivered to the male) are better able to mitigate male harassment. We found support for the hypothesis that some behavioral traits are repeatable in females; however, we found no evidence for behavioral syndromes. We found evidence to suggest that females that are less bold and less aggressive received less mating harassment from males, possibly because those females are of lower quality and not as attractive to males. Our most novel finding in this study was that activity and aggression were both consistent behavioral traits in females, and therefore constitute personalities; however, these personalities did not have a correlation grouping them together into a behavioral syndrome. Maybe there is a tradeoff: good females are bold and aggressive and get more food, but receive more mating harassment, whereas bad females are submissive and get less food, but avoid mating harassment.
|
372 |
Determination of physical characteristics of food fatsZamani, Younes. January 1998 (has links)
No description available.
|
373 |
SNP characterizaiton and genetic and molecular analysis of mutants affecting fiber development in cottonAn, Chuanfu 03 May 2008 (has links)
Cotton (Gossypium spp.) is the world’s leading textile fiber crop, and an important source of oil and protein. Insufficient candidate gene derived-markers suitable for genetic mapping and limited information on genes that control economically important traits are the major impediments to the genetic improvement of Upland cotton (G. hirsutum L.). The objectives of this study were to develop a SNP marker discovery strategy in tetraploid cotton species, SNP characterization and marker development from fiber initiation and elongation related genes, chromosomal assignment of these genes by SNP marker-based deletion analysis or linkage mapping, and genetic and molecular analysis of mutants affecting cotton fiber development. Phylogenetic grouping and comparision to At- and Dt-genome putative ancestral diploid species of allotetraploid cotton facilitated differentiation between genome specific polymorphisms (GSPs) and marker-suitable locus-specific polymorphisms (LSPs). By employing this strategry, a total of 222 and 108 SNPs were identified and the average frequency of SNP was 2.35% and 1.30% in six EXPANSIN A genes and six MYB genes, respectively. Both gene families showed independent and incongruent evolution in the two subgenomes and a faster evolution rate in Dt-genome than that in At-genome. SNPs were concordantly mapped to different chromsomes, which confirmed their value as candidate gene marker and indicated the reliability of SNP discovery stragey. QTL mapping by two F2 populations developed from fiber mutants detected major QTL which explain 62.8-87.1% of the phenotypic variation for lint percentage or lint index in the vicinity of BNL3482-138 on chromosome 26. Single marker regression analyses indicated STV79-108, which was located to the long arm of chromosome 12 (the known location of N1 and perhaps n2 loci), also had significant association (R2 % value 15.4-30.6) with lint percentage, lint index, embryo protein percentage and micronaire. Additional QTL and significant markers associated with other seed and fiber traits were detected on different chromosomes. Inheritance analysis indicated that both genetic models N1N1n2n2 and n2n2li3lisub>3 could lead to the fiberless phenotype. The observation of fuzzless-short lint phenotype indicated fiber initiation and elongation were controlled by different mechanisms. The penetrance of Li2 gene expression was observed in this study.
|
374 |
Structural and functional consequences of disease-related protein variantsLee, Seung-Joo 30 July 2010 (has links)
No description available.
|
375 |
A STUDY OF THE EFFECT OF SINGLE NUCLEOTIDE POLYMORPHISMS IN HUMAN GENOME ON THE SECONDARY STRUCTURE OF PROTEINSAswathanarayanan, Subramanian 21 June 2002 (has links)
No description available.
|
376 |
THE ROLE OF T CELL RECEPTOR Vβ GENE POLYMORPHISMS IN SUSCEPTIBILITY TO JUVENILE RHEUMATOID ARTHRITISBrzezinski, Jennifer Lynn 11 October 2001 (has links)
No description available.
|
377 |
A Study of Genetic Alterations in Cancer ProgressionRamchandani, Divya 11 September 2015 (has links)
No description available.
|
378 |
A Haplotype Analysis of an Archaic Denisovan GenomeYatskiv, Yuriy Romanovich January 2016 (has links)
No description available.
|
379 |
Glutamate Receptor, Ionotropic N-methyl-D-aspartate 2B Polymorphisms and Concussive Recovery in AthletesBright, Nieka L. January 2013 (has links)
Athletes vary in their ability to recover from concussions. Following a concussion, a pathophysiological cascade of events transpires, rendering symptoms. One such event, the indiscriminate release of the excitatory neurotransmitter glutamate, may result in hyperactivation of glutamate receptors (e.g., N-methyl-D-aspartate receptors [NMDARs]) and self-propagate a state of neurotoxicity that may be enhanced via the concomitant release of Ca2+, particularly through NMDARs containing the NR2B subunit. Genetic variation in regulatory regions of the glutamate receptor, ionotropic N-methyl-D-aspartate 2B (GRIN2B) gene, which codes for the NR2B subunit, may play a role in varied recovery among concussed athletes. Indeed, the rs1019385 promoter single nucleotide polymorphism (SNP) has been shown to alter transcription in dominant versus recessive allele carriers such that expression of the T allele results in increased upregulation of the GRIN2B gene. Therefore, the primary purpose of this study was to determine the association of this GRIN2B SNP and concussive recovery; a second GRIN2B SNP (rs890), in the 3'untranslated region, was also explored. A secondary purpose was to examine SNP associations with initial evaluation concussion severity scores. A triple-blind, between-subjects, genetic association design was utilized. The independent variable was genotype for both GRIN2B SNPs (rs1019385, rs890). The primary dependent variable, concussive recovery, was defined as the number of days from the time of injury until full return-to-play (RTP) clearance was granted by a university concussion center's physician; recovery was categorized as either normal (≤ 20 days) or prolonged (> 20 days). The secondary dependent variables were initial evaluation concussion severity scores and consisted of: (a) vestibulo-ocular reflex (VOR) result, (b) Balance Error Scoring System (BESS) sum, and (c) Immediate Postconcussion Assessment and Cognitive Testing (ImPACT) composite scores. Fifty-three, mostly White (69.7%), male (75.0%) concussed athletes (18.96 ± 6.31 years of age) participated in the study; two participants were excluded due to inconclusive genetic results. Participants were evaluated at a university concussion center per standardized concussion assessment battery, using the aforementioned severity indicators, and provided saliva samples for genotyping experiments. Follow-up visits were performed, as needed, until participants were asymptomatic and cleared for full RTP. No significant associations were demonstrated for the codominant (p = .35, p = .70), dominant (p = .39, p = 1.00) or recessive (p = .72, p = .51) genetic models for the rs1019385 and rs890 SNPs (respectively). Similarly, there were no significant differences in any initial evaluation severity scores between genotype for any genetic model. This exploratory study investigated the association between two GRIN2B SNPs and varied concussive recovery among athletes. Although no statistical and minimal clinical significance was demonstrated, future investigations should incorporate a larger sample and next-generation sequencing to investigate the 21,000 to 25,000 genes and their variations across the human genome as complex disorders (e.g., concussions) likely involve a multitude of genetic variations (and their interactions), many with small effects. Further elucidation of genetic factors involved in concussive recovery could equip clinicians with superior counseling methods and treatment options for athletes at-risk for prolonged recovery. / Kinesiology
|
380 |
The impact of variation in the progesterone receptor gene, life history and lifestyle on endometrial function and the menstrual cycleRowe, Elizabeth Jane January 2011 (has links)
Interest in women's reproductive variation within the subfield of Physical Anthropology known as Human Reproductive Ecology is dominated by energetic models for fecundity that disregard genetic variation as a potential cause of differences in reproduction. Further, a strong correlation between ovarian and uterine markers of fecundity is assumed, although this assumption is not supported by the available data. A polymorphism in the progesterone receptor gene, called PROGINS, shows diminished progesterone response in vitro and is associated with a number of uterine disorders in women. To elucidate the discrepancy between ovarian and uterine markers of fecundity, carriers of the PROGINS variant were compared to non-carriers with regard to endometrial thickness and menstrual cycle characteristics. Gene-environment interactions between PROGINS and life history, lifestyle factors, progesterone levels, anthropometric measures, and physical activity were also considered. The PROGINS polymorphism was found to impact both luteal phase length and menses duration, as well as to modify endometrial sensitivity to life history factors, progesterone levels, anthropometric measures, and physical activity. These results support the notion that PROGINS diminishes progesterone response, and indicate that the polymorphism also alters endometrial sensitivity to acute and chronic energetic stress. The findings of this study indicate that Human Reproductive Ecologists must consider genetically-based variation in sensitivity to energetic stress in future adaptive models of women's reproduction. / Anthropology
|
Page generated in 0.0525 seconds