Androgen and estrogen receptors immunolocalization in the sand rat (Psammomys Obesus) cauda epididymis

Progress in research on the reproductive function in the sand rat (Psammomys obesus): A review

The Fat Sand Rat (Psammomys obesus, P. obesus) is a diurnal herbivore and phytophage, with seasonal reproductive behavior. The sexually active phase lasts from autumn to early spring and the sexually inactive phase from late spring to summer. In the past years, P. obesus has gained much attention as an animal model in biological and clinical research. It is a suitable model for diet-induced insulin resistance, non-insulin-dependent diabetes mellitus and obesity studies. In addition, the seasonal reproduction of P. obesus is gaining more and more attention. The current paper aims to review and sum up the progress in the understanding of the reproductive anatomo-histo-physiology of Psammomys obesus, in order to facilitate future research in this area and to expose further perspectives for researchers.

Effects of testosterone on skin structure and factors related to androgen conversion and binding in Hetian sheep

The effects of androgens on human skin mainly include the regulation of growth and differentiation of hair follicles and sebaceous glands. Androgens may have some physiological roles in sheep skin that are similar to those of humans, but further confirmation is needed. Therefore, Hetian sheep were chosen in this study as an animal model to explore the effects of testosterone on skin structure and factors related to androgen conversion and binding in Hetian sheep. The sheep were treated with different concentrations of testosterone for 42 days. Skin tissue sections were prepared and then subjected to hematoxylin-eosin, Sacpic, Masson's trichrome, and Oil Red O staining to observe changes in skin morphology. Changes in the content of blood-related factors were also detected using ELISA kits. The skin tissue distribution of androgen receptor was explored by immunohistochemistry and immunofluorescence assays. The results showed that testosterone significantly increases the sebaceous gland area and stimulates the formation of new sebaceous glands. Further exploration revealed that testosterone promotes the proliferation of sebaceous gland juvenile cells. However, testosterone was found to have no significant effect on hair follicle density and hair follicle structure. Testosterone increased dihydrotestosterone levels but decreased 5α-reductase 1 and 5α-reductase 2 levels. The androgen receptors were distributed in the hair follicles, sebaceous glands, and some major skin appendages of Hetian sheep. This study suggests that androgens can be effective in regulating sebum production in sheep. This study will help advance research efforts to further explore the molecular and cellular mechanisms by which androgens modify sheep follicles and sebaceous glands.

Crucial Convolution: Genetic and Molecular Mechanisms of Coiling during Epididymis Formation and Development in Embryogenesis

As embryonic development proceeds, numerous organs need to coil, bend or fold in order to establish their final shape. Generally, this occurs so as to maximise the surface area for absorption or secretory functions (e.g., in the small and large intestines, kidney or epididymis); however, mechanisms of bending and shaping also occur in other structures, notably the midbrain–hindbrain boundary in some teleost fish models such as zebrafish. In this review, we will examine known genetic and molecular factors that operate to pattern complex, coiled structures, with a primary focus on the epididymis as an excellent model organ to examine coiling. We will also discuss genetic mechanisms involving coiling in the seminiferous tubules and intestine to establish the final form and function of these coiled structures in the mature organism.