ISSN:0192-253X    

DOI:10.1002/dvg.1020090202

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1988

数据来源: WILEY

摘要:

AbstractTheovarian tumorgene behaves as if it encodes a product (OGP), which is required durirng several early steps in the transformation of oogonia into functional oocytes. Seventeen ethyl methane sulfonate‐induced mutations have been studied, and their mutant phenotypes can be explained as graded responses by individual germ cells to different levels of OGP synthesized by the mutant germ cells themselves. The lowest and highest levels of OGP appear to be produced byotu10andotu14, respectively. The 15 mutants with intermediate OGP levels are temperature sensitive; subnormal temperatures improve ovarian development, while above‐normal temperatures suppress it. A subgroup ofthese mutants are unable to form a system of actin microfilament bundles in the cortical cytoplasm of their nurse cells during stage 10B, and these defective nurse cells are unable to transport their cytoplasm to the oocyte, as normally happens between stages 10B and 12. In addition to its role in the actin‐mediated transport of nurse cell cytoplasm, OGP also appears to alter the morphology of giant polytene chromosomes, which form as the nurse cells undergo endocycles of DNA replication. Genetic evidence suggests thatotualso encodes a second product (SP) that is utilized late in oogenesis. SP is required for the synthesis in the ooplasm of glycogen‐rich, beta yolk spheres. Products of theotugene also play a vital but unknown role in embryo

ISSN:0192-253X    

DOI:10.1002/dvg.1020090203

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1988

数据来源: WILEY

摘要:

AbstractThe possible application of microcomputer‐based video‐image analysis systems for the quantitative description of coat‐color patterns in artificially produced chimeras and genetic mosaics of mice was investigated using a program developed by theauthor. This system is capable of extracting, from sampled images of pelts, the morphometric image features as defined by Pratt [1978] that are essential to the quantitative description of coat‐color patterns in these animals. It does so with reasonable accuracy and speed and at low cost. No description of any similar system has been published in the literature. Performance of our system is described using C3H/HeJ ↔BALB/c chimeras as examples.The complex phenotypic expression of hair pigmentation in mice makes the use of a video‐image analysis system like this one essential to evaluate the morphometric parameters of the patterns (e.g., the mixing ratios between the two components, the number of different‐colored stripes, etc.) more precisely and reproducibly than has been done yet in the literature.The results indicate that the number of melanoblast clones in mice, as estimated from the number of minimal recognizable stripes (MRS), might be considerably largerthan previously indicated; the figure presently obtained, i.e., 22.3 ± 2.16 unilaterally in terms of the hypothetical maximum number of stripes (HMNS) (28.73 ± 1.55, after correction for the random clumping) in the thoracicolumbar region of the mouse closely approximates the number of the somites in that region. Concerning the degree of mixing between the two components, it was proposed that the unmixed portion of the components derived from one strain increases in proportion to the second power of the increase in the relative total content of the same components. Work is in progress in our laboratory to analyze a large number of the chimeric pelts using the system describe

ISSN:0192-253X    

DOI:10.1002/dvg.1020090204

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1988

数据来源: WILEY

ISSN:0192-253X    

DOI:10.1002/dvg.1020090201

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1988

数据来源: WILEY