Phylogenetic and population genetic methods that compare nucleic acid variation are being used to identify species and populations of pathogenic fungi and determine how they reproduce in nature. These studies show that asexual or sexual reproductive morphology does not necessarily correlate with clonal or recombining reproductive behavior, and that fungi with all types of reproductive morpholog...

Patterns of reproductive isolation between species may provide insight into the mechanisms and evolution of barriers to interspecific gene exchange. We used data from published interspecific hybridization experiments from 14 genera of angiosperms in order to test for the presence of asymmetrical barriers to gene exchange. Reproductive isolation was examined at three life-history stages: the abi...

A trademark of eusocial insect species is reproductive division of labor, in which workers forego their own reproduction while the queen produces almost all offspring. The presence of the queen is key for maintaining social harmony, but the specific role of the queen in the evolution of eusociality remains unclear. A long-discussed scenario is that a queen either behaviorally or chemically ster...

In this study we compare the reproductive ability of Mastomys natalensis, an agricultural rodent pest and that of the closely related species M. coucha, which has not been ascribed as a pest. We suggest that the ability of M. natalensis to plague, as well as dominate, resource-limited habitats, may in part be related to its differential breeding response to variation in diet quality. Thus, we e...

Age-related improvements in reproductive performance have been explained by the selection, constraint, and restraint hypotheses (increased performance related to greater effort and a declining residual reproductive value). Using a laboratory population of the burying beetle, Nicrophorus orbicollis, 6 measures of performance were assessed. Consideration of the selection and constraint hypotheses...

Reproductive plasticity describes the ability of organisms to adjust parameters such as volume, rate, or timing of progeny production in order to maximize successful reproduction under different environmental conditions. Reproductive plasticity in response to environmental variation has been observed in a wide range of animals; however, the mechanisms involved in translating environmental cues ...

Leptin administration has been shown to prevent the disruptive effects of acute food deprivation on reproductive function in cycling females and lactating females. We examined the ability of intracerebroventricular leptin administration to ameliorate the effects of food restriction for the first 2 wk postpartum on length of lactational infertility. Leptin administration did not reduce the effec...

BACKGROUND Our long-term field survey revealed that the Cardinium infection rate in Bemisia tabaci Q (also known as biotype Q) population was low in Shandong, China over the past few years. We hypothesize that (1) the Cardinium-infected (C+) B. tabaci Q population cannot efficiently compete with the Cardinium-uninfected (C-) B. tabaci Q population; (2) no reproductive isolation may have occurre...

There has been a significant decline in the reproductive performance of dairy cattle in recent decades. Cows, take longer time to return to the oestrus after calving, have poorer conception rates, and show fewer signs of oestrus. Achieving good reproductive performance is an increasing challenge for the dairy producer. In this study we focus on understanding the overall biological phenomena ass...

This qualitative study in the Islamic Republic of Iran aimed to explore facilitators and barriers to the use of reproductive health services by unmarried women. A purposive sample of unmarried women aged 25-60 years in Isfahan city were interviewed about their experiences of reproductive health services in public health centres. Content analysis of responses revealed that the favourable charact...