The overall sex ratio of offspring （dead embryos and hatch chicks） from all the fertilized eggs of 140 hens collected for 30 days was studied using duplex PCR of certain fragments of sex chromosomes. Additional 894 ...The overall sex ratio of offspring （dead embryos and hatch chicks） from all the fertilized eggs of 140 hens collected for 30 days was studied using duplex PCR of certain fragments of sex chromosomes. Additional 894 dead embryos over a period of 21 days of incubation were also investigated to verify the sex ratio of the dead embryos. The sex of the early dead embryos was identified using this molecular sexing technique. The sex ratio of the hatch chicks and the total offspring of the hens investigated in this experiment did not differ from the expected sex ratio （i.e., 1：1）., However, the number of female dead embryos was significantly more than that of males. The data indicated that the different physiologic function of males and females contributed to female-biased mortality during incubation. It was also found by further analysis that the sex ratios of the offspring of some hens were significantly biased to female or male over the period investigated, which suggested that the sex ratio of offspring might be influenced by the maternal condition to some degrees.展开更多
Recent studies investigating possible causes of male subfertility have largely focused on how lifestyle or environmental factors impact on the process of spermatogenesis, Markedly, fewer studies have investigated thos...Recent studies investigating possible causes of male subfertility have largely focused on how lifestyle or environmental factors impact on the process of spermatogenesis, Markedly, fewer studies have investigated those risk factors that result in reduced sperm quality, such as poor sperm motility. The speed at which sperm swim is a major predictor of fertility and is extremely variable in human populations. It has been hypothesized that offspring sex may be adaptively manipulated to maximize the offspring＇s reproductive fitness （e.g., parents with genes for good male fertility traits, such as high sperm speed, would produce primarily sons and fewer daughters because the offspring will inherit advantageous male fertility genes）. Conversely, parents with poor male fertility genes would produce primarily daughters, We tested whether there was an association between how fast a man＇s sperm swam and the sex bias of his siblings in a sample of men attending clinic for fertility investigations with their partner and with a wide range of semen characteristics, including sperm speed. We found that the sex bias of a man＇s siblings is associated with his sperm speed; men with female-biased siblings had significantly slower sperm （judged using computer-assisted sperm analysis （CASA）） than men from male-biased sibships. This observation suggests family composition is an important factor that needs to be considered in future eDidemiological and clinical studies of human fertility,展开更多
文摘The overall sex ratio of offspring （dead embryos and hatch chicks） from all the fertilized eggs of 140 hens collected for 30 days was studied using duplex PCR of certain fragments of sex chromosomes. Additional 894 dead embryos over a period of 21 days of incubation were also investigated to verify the sex ratio of the dead embryos. The sex of the early dead embryos was identified using this molecular sexing technique. The sex ratio of the hatch chicks and the total offspring of the hens investigated in this experiment did not differ from the expected sex ratio （i.e., 1：1）., However, the number of female dead embryos was significantly more than that of males. The data indicated that the different physiologic function of males and females contributed to female-biased mortality during incubation. It was also found by further analysis that the sex ratios of the offspring of some hens were significantly biased to female or male over the period investigated, which suggested that the sex ratio of offspring might be influenced by the maternal condition to some degrees.
文摘Recent studies investigating possible causes of male subfertility have largely focused on how lifestyle or environmental factors impact on the process of spermatogenesis, Markedly, fewer studies have investigated those risk factors that result in reduced sperm quality, such as poor sperm motility. The speed at which sperm swim is a major predictor of fertility and is extremely variable in human populations. It has been hypothesized that offspring sex may be adaptively manipulated to maximize the offspring＇s reproductive fitness （e.g., parents with genes for good male fertility traits, such as high sperm speed, would produce primarily sons and fewer daughters because the offspring will inherit advantageous male fertility genes）. Conversely, parents with poor male fertility genes would produce primarily daughters, We tested whether there was an association between how fast a man＇s sperm swam and the sex bias of his siblings in a sample of men attending clinic for fertility investigations with their partner and with a wide range of semen characteristics, including sperm speed. We found that the sex bias of a man＇s siblings is associated with his sperm speed; men with female-biased siblings had significantly slower sperm （judged using computer-assisted sperm analysis （CASA）） than men from male-biased sibships. This observation suggests family composition is an important factor that needs to be considered in future eDidemiological and clinical studies of human fertility,
