The ability of germ cells to carry out a gene regulatory program distinct from the surrounding somatic tissue, and their capacity to specify an entire new organism has made them a focus of many studies that seek to understand how specific regulatory mechanisms, particularly post-transcriptional mechanisms, contribute to cell fate. In zebrafish, germ cells are specified through the inheritance o...

Gonadal development, germ cell differentiation and the appearance of membrane antigenic determinants, specific for male and female germ cells during gonadogenesis, was studied in larval and juvenile carp (Cyprinus carpio L.) until 25 weeks after fertilization. Indirect immunofluorescence studies with four monoclonal antibodies raised against carp spermatozoa revealed that monoclonal antibody WC...

The fetal gonad is composed of a mixture of somatic cell lineages and germ cells. The fate of the gonad, male or female, is determined by a population of somatic cells that differentiate into Sertoli or granulosa cells and direct testis or ovary development. It is well established that germ cells are not required for the establishment or maintenance of Sertoli cells or testis cords in the male ...

abstract diabetes mellitus (dm) is one of the greatest public health threats in modern societies. although during a few years it was suggested that dm had no significant effect in male reproductive function, this view has been challenged in recent years. from a clinical perspective, the evaluation of semen parameters, as well as spermatozoa deoxyribonucleic acid (dna) integrity, are often studi...

The initial effect of u.v. irradiation of the vegetal pole was to inhibit cleavage in the vegetal hemisphere although karyokinesis was not substantially affected. In this way a syncytium formed in the vegetal hemisphere which broke down into individual cells some time between morula and late blastula. The movement of the germ plasm from the peripheral cortical regions into the interior of the e...

We discovered that a 150-bp region of zebrafish deadend (dnd) spanning the translation start codon, exon 1 and part of intron 1 is required to direct heterologous neomycin-resistance gene (neo) expression specifically in the gonad, similar to endogenous dnd. Using an 8.3-kb dnd promoter that contains this 150-bp region, we generated Tg(dnd:neo-dnd) transgenic zebrafish in which the expression o...

Germ cells may be specified through the localization of germ line determinants to specific cells in early embryogenesis, or by inductive signals from neighboring cells to germ cell precursors in later embryogenesis. Such determinants can be produced and localized during or after oogenesis, either autonomously by oocytes or by associated nutritive cells. In Drosophila, each oocyte is connected t...

Individuals with various intersex states who carry Y-chromosome material bear a high risk of developing testicular neoplasia. In order to gain more insight into the pathogenesis of this neoplasia, the current study evaluates the differentiation of the seminiferous epithelium in 46,XY dysgenetic male pseudohermaphroditism. Immunohistochemical evaluation was performed using the germ cell-specific...