The relationship between cytoplasmic incompatibility and the obligate intracellular alphaproteobacteria Wolbachia has for a long time been reported. Although molecular mechanisms responsible this reproductive alteration are beginning to be understood, effects of on germ cell structure dynamics have not yet fully investigated. We report here that presence in infected cysts elongating spermatids ...

Background Chromatin of male and female gametes undergoes a number of reprogramming events during the transition from germ cell to embryonic developmental programs in the zygote. This process involves reorganisation of the patterns of 5-methylcytosine (5mC), a DNA modification associated with regulation of gene activity. Notably, both maternal and paternal genomes undergo Tet3-dependent oxidati...

Hop-sterile (hop) is a new mutation in the mouse, the effects of which include complete male sterility, a 'hopping' gait and preaxial polydactyly of all feet. Ultrastructural studies of spermiogenesis show that sperm tails are absent or highly modified. Second meiotic division is frequently abnormal or incomplete, often with four centrioles per cell. These centrioles usually fail to form fiagel...

In spite of the availability of abundant data about in vitro spermatogenesis in laboratory animals, studies on human in vitro spermatogenesis are scarce. This study employed a relatively simple culture system, involving all cell types of seminiferous tubules, to analyze the effects of FSH and testosterone (T) on different characteristics of human germ and Sertoli cells in culture. By using fluo...

Krüppel-like factor 4 (Klf4, GKLF) was originally characterized as a zinc finger transcription factor essential for terminal differentiation and cell lineage allocation of several cell types in the mouse. Mice lacking Klf4 die postnatally within hours due to impaired skin barrier function and subsequent dehydration. Recently, KLF4 was also used in cooperation with other transcription factors to...

Autoradiographic and electron microscope methods were used to correlate changes in nucleoproteins with nuclear fine structure during spermatogenesis in the mouse. Testes were fixed at daily intervals after intratesticular injectionwith labeled amino acid. [3H]Arginine, lysine, valine, and proline were rapidly incorporated into primary spermatocyte nuclei, retained through subsequent spermatocyt...

Males of Limnogonus aduncus were found to have the sex chromosome system X0 and chromosome number 2n = 23 (22A + X0). Testis cells were stained with lacto-acetic orcein and silver nitrate so that changes in the morphology and degree of staining of the heteropicnotic chromatin and the nucleolar material could be observed during meiosis and spermiogenesis. These structures share the same nuclear ...

Spermatozoa are more efficient at supporting normal embryonic development than spermatids, their immature, immediate precursors. This suggests that the sperm acquires the ability to support embryonic development during spermiogenesis (spermatid to sperm maturation). Here, using Xenopus laevis as a model organism, we performed 2-D Fluorescence Difference Gel Electrophoresis (2D-DIGE) and mass sp...

Krüppel-like factor 4 (KLF4) is a transcription factor involved in many cellular and developmental processes such as terminal differentiation of cells and carcinogenesis. Mice lacking KLF4 die post-natally due to skin barrier deficiencies and exhibit several additional cellular defects. The adult rodent testis expresses high levels of Klf4 mRNA. Using in situ hybridization, we previously locali...

OBJECTIVE To examine whether the results of assisted reproduction with the use of elongated spermatids from a man with incomplete arrest of spermiogenesis and a high frequency of apoptosis among postmeiotic germ cells can be improved by germ cell in vitro culture. DESIGN Case report. SETTING Private assisted reproduction centers and a university department. PATIENT(S) Man with incomplete ...