scholarly journals A QTL analysis of female variation contributing to refractoriness and sperm competition in Drosophila melanogaster

2005 ◽  
Vol 86 (2) ◽  
pp. 107-114 ◽  
Author(s):  
MARA K. N. LAWNICZAK ◽  
DAVID J. BEGUN
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Variation ◽  
Sperm Competition ◽  
Competitive Ability ◽  
Recombinant Inbred Lines ◽  
Inbred Lines ◽  
Phenotypic Variance ◽  
Fitness Component ◽  
Male Sperm ◽  
Trait Locus

Sperm competition is an important fitness component in many animal groups. Drosophila melanogaster males exhibit substantial genetic variation for sperm competitive ability and females show considerable genetic variation for first versus second male sperm use. Currently, the forces responsible for maintaining genetic variation in sperm competition related phenotypes are receiving much attention. While several candidate genes contributing to the variation seen in male competitive ability are known, genes involved in female sperm use remain largely undiscovered. Without knowledge of the underlying genes, it will be difficult to distinguish between different models of sexual selection such as cryptic female choice and sexual conflict. We used quantitative trait locus (QTL) mapping to identify regions of the genome contributing to female propensity to use first or second male sperm, female refractoriness to re-mating, and early-life fertility. The most well supported markers influencing the phenotypes include 33F/34A (P2), 57B (refractoriness) and 23F/24A (fertility). Between 10% and 15% of the phenotypic variance observed in these recombinant inbred lines was explained by these individual QTLs. More detailed investigation of the regions detected in this experiment may lead to the identification of genes responsible for the QTLs identified here.

scholarly journals Quantitative trait locus mapping of gravitaxis behaviour in Drosophila melanogaster

2010 ◽  
Vol 92 (3) ◽  
pp. 167-174 ◽  
Author(s):  
CHRISTIE E. DESROCHES ◽  
MACARENA BUSTO ◽  
CRAIG A. L. RIEDL ◽  
TRUDY F. C. MACKAY ◽  
MARLA B. SOKOLOWSKI
Keyword(s):  
Drosophila Melanogaster ◽  
Candidate Genes ◽  
Quantitative Trait ◽  
Gravitational Force ◽  
Recombinant Inbred Lines ◽  
Inbred Lines ◽  
Chordotonal Organ ◽  
Trait Locus ◽  
Sense And Respond ◽  
Locus Mapping

SummaryDrosophila melanogaster, like other organisms, move and orient themselves in response to the earth's gravitational force. The ability to sense and respond to gravity is essential for an organism to navigate and thrive in its environment. The genes underlying this behaviour in Drosophila remain elusive. Using 88 recombinant inbred lines, we have identified four quantitative trait loci (QTLs) that contribute to adult gravitaxis (geotaxis) behaviour in Drosophila. Candidate genes of interest were selected from the QTLs of highest significance based on their function in chordotonal organ formation. Quantitative complementation tests with these candidate genes revealed a role for skittles in adult gravitaxis behaviour in D. melanogaster.

scholarly journals Evolution of sperm competition: Natural variation and genetic determinants of Caenorhabditis elegans sperm size

2018 ◽  
Author(s):  
Clotilde Gimond ◽  
Anne Vielle ◽  
Nuno Silva-Soares ◽  
Stefan Zdraljevic ◽  
Patrick T. McGrath ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Sperm Competition ◽  
Natural Variation ◽  
Competitive Ability ◽  
Molecular Mechanisms ◽  
Genetic Determinants ◽  
Heritable Variation ◽  
C Elegans ◽  
Male Sperm ◽  
Sperm Size

ABSTRACTSperm morphology is critical for sperm competition and thus for reproductive fitness. In the male-hermaphrodite nematode Caenorhabditis elegans, sperm size is a key feature of sperm competitive ability. Yet despite extensive research, the molecular mechanisms regulating C. elegans sperm size and the genetic basis underlying its natural variation remain unknown. Examining 97 genetically distinct C. elegans strains, we observe significant heritable variation in male sperm size but genome-wide association mapping did not yield any QTL (Quantitative Trait Loci). While we confirm larger male sperm to consistently outcompete smaller hermaphrodite sperm, we find natural variation in male sperm size to poorly predict male fertility and competitive ability. In addition, although hermaphrodite sperm size also shows significant natural variation, male and hermaphrodite sperm size do not correlate, implying a sex-specific genetic regulation of sperm size. To elucidate the molecular basis of intraspecific sperm size variation, we focused on recently diverged laboratory strains, which evolved extreme sperm size differences. Using mutants and quantitative complementation tests, we demonstrate that variation in the gene nurf-1 – previously shown to underlie the evolution of improved hermaphrodite reproduction – also explains the evolution of reduced male sperm size. This result illustrates how adaptive changes in C. elegans hermaphrodite function can cause the deterioration of a male-specific fitness trait due to a sexually antagonistic variant, representing an example of intralocus sexual conflict with resolution at the molecular level. Our results further provide first insights into the genetic determinants of C. elegans sperm size, pointing at an involvement of the NURF chromatin remodelling complex.

scholarly journals QTLs for resistance to soybean cyst nematode, races 3, 9, and 14 in cultivar Hartwig

2011 ◽  
Vol 46 (4) ◽  
pp. 420-428 ◽  
Author(s):  
Marcia Flores da Silva Ferreira ◽  
Gerardo Domingo Lucio Cervigni ◽  
Adésio Ferreira ◽  
Ivan Schuster ◽  
Fernanda Abreu Santana ◽  
...  
Keyword(s):  
Soybean Cyst Nematode ◽  
Recombinant Inbred Lines ◽  
Inbred Lines ◽  
Cyst Nematode ◽  
Minor Effect ◽  
Phenotypic Variance ◽  
Linkage Groups ◽  
Resistance Qtls ◽  
Epistatic Interactions ◽  
Genomic Regions

The objective of this work was to identify major and minor-effect quantitative trait loci (QTL) for resistance to races 3, 9, and 14 of soybean cyst nematode (SCN) in Hartwig cultivar; to map new resistance QTLs for these races; and to check for the existence of epistatic interactions between QTLs. Cultivar Hartwig is an important resistance source to SCN. Recombinant inbred lines (RIL) obtained from a cross between 'Hartwig' (resistant) and Y23 (susceptible) were evaluated regarding resistance to the three races. New genomic regions for resistance to SCN were identified by microsatellites. Four QTLs, which explained between 12 and 34% of phenotypic variance, were detected for resistance to race 3 in linkage groups (LG) A2, G, J, and M. The QTL in LG G is also important for resistance to race 9. Epistatic interactions were detected between loci, which indicate resistance to races 9 and 14. There are high and low-effect resistance QTLs to SCN.

Sign in / Sign up

Export Citation Format

Share Document