Reproduction, Fertility and Development
Volume 32
Number 11 2020
Early pregnancy diagnosis in cattle operations allows non-pregnant females to be rapidly detected, allowing new chances of conception in a shorter period. To develop a method to diagnose pregnancy earlier, it is necessary to understand the stimulatory effects of the conceptus on the maternal organism. In this study we found that both circulating peripheral blood mononuclear cells and polymorphonuclear leucocytes respond to the presence of the bovine conceptus by increasing expression of interferon-τ-stimulated genes up to 10 days before pregnancy can be detected when using conventional methods.
Lipid droplets in fat cells and non-fat cells are sources of energy and fatty acid hormone production, but whether there are lipid droplets in the uterine cervix and whether lipid droplets are in a degraded state are remain unclear. The findings of this study suggest that lipid droplets are in a degraded state during pregnancy and this is controlled by progesterone. Thus, lipid droplets could play an important role in maintaining cervical closure during gestation.
In contrast with other mammals, dogs exhibit a delay in oocyte maturation that has not been fully elucidated. We characterised the pattern of intracellular communication between the oocyte and its companion somatic cell compartment, or cumulus cells, via the expression of connexin 43 and 37 gap junctions. This study advances of understanding of the complex dynamics of dog follicular growth through the connexin gap junctions. Maintenance of connexin expression before ovulation indicates the involvement of connexins 43 and 37 in the prolonged meiotic arrest.
Sperm production and male fertility depend on several factors in addition to testosterone. In this study we investigated the insulin-like growth factors that are important regulators of testicular function and found that they can control the proliferation and death of germ cells during the reproductive cycle in a fish species. These results can be applied to fish farming in order to increase the production of fish for human consumption and the conservation of endangered species.
The BMP15 gene is crucial for female fecundity, but its role in male reproduction remains unclear. A BMP15 knockdown pig model was generated to determine its effect on boar fertility. The boar was fertile with normal testicular development but decreased sperm viability. The study provides new insights into the role of BMP15 in male reproduction.
Successful in vitro production (IVP) of equine embryos requires meticulous incubation conditions for both overnight holding and maturation of immature oocytes. Developmental competence can be improved by holding temperature as well as media alternatives that regulate the resumption of meiosis and support cleavage and blastocyst production. As the horse breeding industry requests IVP embryos to preserve valuable genetic lines, these improvements may optimise the outcome of embryos produced in vitro.
Information about changes in lipid accumulation during oocyte growth phases and the localisation of lipids in the cytoplasm is scarce. This study evaluated the morphological distribution and size of lipid droplets in young and adult ovine oocytes recovered during the growing phases. The findings of this study support the metabolic activities that take place during folliculogenesis.