Histomorphological Comparisons and Expression Patterns of BOLL Gene in Sheep Testes at Different Development Stages

Abstract

BOLL is implicated in mammalian testicular function maintenance and spermatogenesis. To understand the expression patterns and biological functions of sheep BOLL, we examined the expression and immunolocalization of BOLL in the developing testes of Small-Tail Han sheep aged 0 days (D0), 2 months (2M), 5 months (5M), 1 year (1Y), and 2 years (2Y), by qPCR, Western blot, and immunohistochemistry methods. Firstly, morphological studies revealed that, in addition to spermatogonia, ordered and clear spermatocytes, as well as round and elongated spermatids and sperm, were found in the 1Y and 2Y testicular seminiferous tubules of the sheep testes, compared with the D0, 2M, and 5M testes, as analyzed by hematoxylin and eosin (H&E) staining. The diameter and area of the seminiferous tubules, epithelial thickness, and the area and perimeter of the tubule lumens gradually increased with age. BOLL was specifically expressed in testes and upregulation of BOLL transcript expression was higher in the testes of the 1Y and 2Y groups than in those of the D0, 2M, and 5M groups. Similarly, BOLL protein was expressed mainly in the 1Y and 2Y testes, ranging from primary spermatocytes to round spermatids, as well as in the spermatozoa. This study is the first demonstration that sheep BOLL might serve as a key regulator of the spermiogenesis involved in sperm maturity, in addition to its role as a crucial meiotic regulator.

Deletion of porcine BOLL is associated with defective acrosomes and subfertility in Yorkshire boars

“…Considering that the sperm count in ejaculates of boars with the KAD is normal (Kopp et al 2008), absence of BOLL does not seem to affect meiotic progression in pigs. Thus, our findings corroborate that the role of BOLL during spermatogenesis and sperm maturation may vary between species (Li et al 2019) and warrant further research to elucidate its precise function in pigs.…”

“…Thus, our findings corroborate that the role of BOLL during spermatogenesis and sperm maturation may vary between species (Li et al . 2019) and warrant further research to elucidate its precise function in pigs.…”

Deletion of porcine BOLL causes defective acrosomes and subfertility in Yorkshire boars

“…The sperm count in ejaculates of boars with the KAD was not reduced (Kopp et al, 2008), suggesting that absence of BOLL does not notably affect meiotic progression in pigs. Thus, our findings corroborate that the role of BOLL during spermatogenesis and sperm maturation may vary between species (Li et al, 2019) and warrant further research to elucidate its precise function in pigs.…”

Morphometric Evaluation of Spermatogenic Cells and Seminiferous Tubules and Exploration of Luteinizing Hormone Beta Polypeptide in Testis of Datong Yak

“…The testicle samples were maintained in 4% neutral buffered formalin for fixation overnight and later embedded in paraffin wax. The sections were cut into 5 µm slices, and then, sections were dehydrated in alcohol grading series (75-100%) for 2 min in each alcohol grade, as described by Taotao et al [19]. Then, these sections were stained with hematoxylin and eosin (H&E): Harry's hematoxylin for 2 min and 1% eosin for 30 s. Light microscopy analysis was conducted using an Olympus microscope (BX53) and camera (Olympus DP73, Tokyo, Japan).…”