Search results for "Mating"
showing 10 items of 387 documents
Studies on the laboratory mating habits of the mosquito Culex pipiens
2009
SYNOPSIS The variation in copulatory activity in three strains of Culex pipiens is investigated and the results are discussed in relation to genetic control of mosquito populations.
Mating strategies and resulting patterns in mate guarding crustaceans : an empirical and theoretical approach
2012
Because of strong costs associated with each mating event, females are usually not as available for reproduction as males at any given time. Males are therefore in competition with each other for access to receptive females, hence leading to strong sexual selection. One textbook case of such a mating system occurs in moulting crustaceans where females can only be fertilized during a short period following their moult. This has favoured the evolution male strategies to monopolize females before their period of receptivity. Such a precopulatory mate guarding is widespread among many taxa and represents one of the most striking example of males’ competitive traits favoured by sexual selection.…
Effect of host plant quality on male sexual performances and consequences on female reproductive output in a phytophagous moth
2016
The abundance of phytophagous insects is determined by numerous interacting biotic and abiotic factors. In capital-breeding phytophagous insects, larval host plant quality is a key determinant of the adult phenotype and the performance of both males and females. Curiously, if the effect of host plant quality on female reproductive success is well-established, little effort has been conducted to determine this effect on male reproductive success. Moreover, in Lepidoptera, males transfer to females a spermatophore containing sperm and accessory gland products rich in nutrients that could be reinvested into female reproduction. The aim of this thesis was to evaluate how male larval nutrition o…
SEQUENCE EVOLUTION OF THE SPERM LIGAND ZONADHESIN CORRELATES NEGATIVELY WITH BODY WEIGHT DIMORPHISM IN PRIMATES
2007
Sexual selection has repeatedly been shown to be the probable driving force behind the positive Darwinian evolution of genes affecting male reproductive success. Here we compare the sequence evolution of the sperm ligand zonadhesin with body mass dimorphism in primates. In contrast to previous related studies, the present approach takes into account not only catarrhine primates, but also platyrrhines and lemurs. In detail, we analyze the sequence evolution of concatenated zonadhesin fragments (555 bp) of four Lemuroidea, five Platyrrhini, and seven Catarrhini, using the rate ratio of nonsynonymous to synonymous substitutions (dn/ds=omega). Unexpectedly, subsequent regression analyzes betwee…
No evidence for an indirect benefit from female mate preference in Arctic charr Salvelinus alpinus, but female ornamentation decreases offspring viab…
2011
Female mate choice is considered an important evolutionary agent, but there has been an ongoing debate over the fitness consequences it produces, especially in species that have a resource-free mating system. We examined a potential fitness benefit resulting from the pre-spawning mate preference in Arctic charr Salvelinus alpinus, a salmonid fish with no parental care. The females were first allowed to discriminate behaviourally between two males presented to them in a free choice test. We then tested with controlled fertilizations whether the females would accrue indirect genetic benefits for their offspring, as measured by embryonic viability, if they had mated with the male they preferre…
Improving Reliability of Road Safety Estimates Based on High Correlated Accident Counts
2007
Calibrating a safety performance function (SPF) with many years of accident data creates a temporal correlation that traditional model calibration procedures cannot deal with. It is well known that generalized estimating equations (GEE) models are able to incorporate trends into accident data and thus overcome difficulties in accounting for correlation; the usual application of GEEs to safety analysis uses robust (or sandwich) estimates of regression coefficients under the independence hypothesis for the working correlation matrix. This practice is justified by the robustness of the GEE procedure against misspecification of the response correlation structure. Nevertheless, with this method…
Physiological and genomic characterisation of Saccharomyces cerevisiae hybrids with improved fermentation performance and mannoprotein release capaci…
2015
Yeast mannoproteins contribute to several aspects of wine quality by protecting wine against protein haze, reducing astringency, retaining aroma compounds and stimulating lactic-acid bacteria growth. The selection of a yeast strain that simultaneously overproduces mannoproteins and presents good fermentative characteristics is a difficult task. In this work, a Saccharomyces cerevisiae × S. cerevisiae hybrid bearing the two oenologically relevant features was constructed. According to the genomic characterisation of the hybrids, different copy numbers of some genes probably related with these physiological features were detected. The hybrid shared not only a similar copy number of genes SPR1…
Regulation of mating in the budding yeast Saccharomyces cerevisiae by the zinc cluster proteins Sut1 and Sut2
2013
This article is made available through the Brunel Open Access Publishing Fund. Copyright @ The Authors. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. The zinc cluster proteins Sut1 and Sut2 play a role in sterol uptake and filamentous growth in the budding yeast Saccharomyces cerevisiae. In this study, we show that they are also involved in mating. Cells that lack both SUT1 and SUT2 were defective in mating. The expression of the genes NCE102 and PRR2 was increased in the sut1 sut2 double deletion mutant…
Mate Sampling and Assessment Procedures in Female Pied Flycatchers (Ficedula hypoleuca)
2010
Models of mate sampling strategies predict that choosiness should decrease throughout the breeding season due to increasing costs of delaying mating. Therefore, individuals who start searching mates relatively late, should spend less time on sampling, and sample fewer candidates compared to early individuals. We observed mate searching behavior of female pied flycatchers (Ficedula hypoleuca) by radio-tracking in study areas with 6–12 unpaired males. Contrary to the prediction, the observed numbers of males sampled by the searching females increased with time, i.e. late arriving females visited more males than early arrivers. However, this seems to be due to more active sampling of males in …
El «apareamiento oral» (oris coitus) de las serpientes y su simbología en la literatura emblemática neolatina
2009
Este artículo trata del denominado «apareamiento por la boca» (oriscoitus) de las serpientes y su simbología en los libros de emblemas latinos de los siglos XVI y XVII, revisando las diferentes interpretaciones que los autores ofrecen de este ancestral argumento e identificando las fuentes (literarias y gráficas) clásicas, medievales y renacentistas. Asimismo, se establecen las curiosas imbricaciones que presenta tal metáfora con arquetipos míticos. This paper is about the so called «oral mating» (oris coitus) of the serpents and its symbolism in the books of Latin emblems of the XVIth and XVIIth century, revising the different interpretations that the authors offer of this ancient argument…