A survey of empirical studies relating mating and parental investment reveals as many unpredicted patterns as results supporting existing hypotheses. This leaves us with individual post hoc explanations of observed patterns rather than an ability to make strong a priori predictions. I argue here that our ability to explain and predict empirical patterns can be improved by considering how social...

A total of 29 SPF Large White prepuberal gilts (mean age 152 days at treatment) were examined for estrous and ovulatory responses after PG 600 treatment. After treatment, 85.2% of the gilts showed standing estrus within 6 days. Whereas the treatment-to-estrus interval and duration were 3.7 and 1.9 days respectively. As ovulation occurred on Day 5 to 6, appropriate timing of artificial inseminat...

Variation in reproductive success has long been thought to be mediated in part by genes encoding seminal proteins. Here we explore the effect on male reproductive phenotypes of X-linked polymorphisms, a chromosome that is depauperate in genes encoding seminal proteins. Using 57 X chromosome substitution lines, sperm competition was tested both when the males from the wild-extracted line were th...

G-Protein Subunit of Cochliobolus heterostrophus Involved in Virulence, Asexual and Sexual Reproductive Ability, and Morphogenesis Sherif Ganem,†‡ Shun-Wen Lu,† Bee-Na Lee,§ David Yu-Te Chou,¶ Ruthi Hadar, B. Gillian Turgeon, and Benjamin A. Horwitz* Department of Biology, Technion-Israel Institute of Technology, Haifa, Israel, Department of Plant Pathology, Cornell University, Ithaca, New York...

Earthworms are the most suitable biological indicators of radioactive pollution because they are the parts of nutritional webs, and are present in relatively high numbers. Four months old Eisenia fetida were exposed to different doses of gamma radiation, namely 1, 2, 3, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55 & 60 Gy to study the effects of radiation on different reproductive parameters. The ...

OBJECTIVES Young people in Tanzania are known to access reproductive health services from a range of close-to-community providers outside formal health settings such as drug stores, village AIDS committees, traditional healers and traditional birth attendants (TBAs). However, questions remain about the quality of services such agents provide. This study investigated their capacity to provide ad...

In 2007, seven detector dogs were produced by somatic cell nuclear transfer using one nuclear donor dog, then trained and certified as excellent detector dogs, similar to their donor. In 2011, we crossed a cloned male and normal female by natural breeding and produced ten offspring. In this study, we investigated the puppies' temperaments, which we later compared with those of the cloned parent...

In most vertebrates, production of reproductive hormones wanes with age, co-occurring with a decline in reproductive output. Measurement of these hormones can serve as a key marker of the onset of reproductive senescence. Longitudinal studies of physiological parameters in populations of free-living animals are relatively uncommon; however, we have monitored baseline concentrations of hormones ...

There is substantial scientific and public concern about the potential effects of occupational and environmental toxicants on reproductive health. These effects include impaired functioning of the reproductive systems of men and women as well as a broad spectrum of developmental problems expressed in offspring. Research on reproduction and development is among the most complex undertakings in b...

The female reproductive tract is commonly referred to as oviduct in birds. The oviduct is a highly convoluted muscular duct, concerned with the transport of the ovum away from the ovary, with fertilization of the ovum and by the deposition of albumen, membranes and shell on to the ovum to form the finished egg [1]. Reproductive diseases in poultry causes high morbidity (35%), mortality (15%) an...