39 research outputs found
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Testicular degeneration in Bclw-deficient mice
To identify genes required for mammalian spermatogenesis, we screened lines of mutant mice created using a retroviral gene-trap system for male infertility. Homozygous ROSA41 male mice exhibit sterility associated with progressive testicular degeneration. Germ-cell defects are first observed at 19 days post-natal (p19). Spermatogenesis is blocked during late spermiogenesis in young adults. Gradual depletion of all stages of germ cells results in a Sertoli-cell-only phenotype by approximately six months of age. Subsequently, almost all Sertoli cells are lost from the seminiferous tubules and the Leydig cell population is reduced. Molecular analysis indicates that the gene mutated is Bclw, a death-protecting member of the Bcl2 family. The mutant allele of Bclw in ROSA41 does not produce a Bclw polypeptide. Expression of Bclw in the testis appears to be restricted to elongating spermatids and Sertoli cells. Potential roles for Bclw in testicular function are discussed
The development and application of bioinformatics core competencies to improve bioinformatics training and education
Bioinformatics is recognized as part of the essential knowledge base of numerous career paths in biomedical research and healthcare. However, there is little agreement in the field over what that knowledge entails or how best to provide it. These disagreements are compounded by the wide range of populations in need of bioinformatics training, with divergent prior backgrounds and intended application areas. The Curriculum Task Force of the International Society of Computational Biology (ISCB) Education Committee has sought to provide a framework for training needs and curricula in terms of a set of bioinformatics core competencies that cut across many user personas and training programs. The initial competencies developed based on surveys of employers and training programs have since been refined through a multiyear process of community engagement. This report describes the current status of the competencies and presents a series of use cases illustrating how they are being applied in diverse training contexts. These use cases are intended to demonstrate how others can make use of the competencies and engage in the process of their continuing refinement and application. The report concludes with a consideration of remaining challenges and future plans
Spermatogonial transplantation - an update for the millennium
Spermatogonial transplantation as developed in the laboratory of Ralph
Brinster has been a technological breakthrough in the study of
Sertoli-germ cell interactions. For the first time, germ cells can be
transferred from one animal to another and from one species to another.
The transfer technology combined with developments in freezing germ cells,
long-term culture of germ cells, and enrichment of stem cell populations
portend even more significant breakthroughs in the new millennium. The
ultimate application of germ cell transfer would allow the in vitro
genetic manipulation of cultured stem cells that could then be
transplanted into recipient syngeneic or xenogeneic recipients and give
rise to functional male gametes. Clearly, this achievement would have
applications in basic science, human medicine, and domestic and wild
animal reproduction. While progress in this direction has been significant
and swift, significant barriers such as immunological response and
mechanisms for introducing genetic material into the stem cells remain to
be examined. This report is a chronological review of the technological
advances made and conceptual insights gained since the first report of
successful transplantation in 1994
Electron microscopy : principles and techniques for biologists
Bibliografi hlm. Setiap babxxiii, 670 hlm. :il. ;28 cm
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