GENETICS OF THE PATERNAL SEX RATIO CHROMOSOME

父系染色体性别比的遗传学

• 批准号: 3324802
• 负责人: JOHN Haynes WERREN
• 金额: $ 12.87万
• 依托单位: UNIVERSITY OF ROCHESTER
• 依托单位国家: 美国
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-08-01 至 1992-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3324802
• 关键词: Hymenoptera; biochemical evolution; chromosome aberrations; chromosome deletion; complementary DNA; cytogenetics; developmental genetics; extrachromosomal DNA; gel electrophoresis; gene complementation; genetic library; genetic manipulation; genetic mapping; genetic transcription; in situ hybridization; insect control; molecular genetics; molecular site; mutagen testing; nucleic acid probes; pest control; radionuclides; sex chromosomes; sex determination; spermatogenesis; structural genes

Psr (paternal sex ratio) is a supernumerary (of B) chromosome in the parasitic wasp. Nasonia vitripennis, which is inherited through sperm but then causes the paternal chromosomes to condense into a chromatin mass prior to the first cleavage division. The paternal chromosomes are eventually lost, but the psr chromosome survives and is transmitted to the next generation. Normally males are derived from unfertilized (haploid) eggs while females are derived from fertilized (diploid) eggs in this wasp. Thus, the affect of psr is to convert diploid female eggs into haploid eggs which develop into psr males. The system is important for two reasons. First, psr is a discrete genetic element that causes paternal chromosome condensation and inactivation during mitosis in the fertilized eggs. It is therefore a tractable system to study genetics of chromosome imprinting and chromosome inactivation. Second, psr is the most extreme example of a "selfish" genetic element so far described. Therefore, genetic studies of psr will increase our understanding of how these elements evolve and function. Research will be undertaken to answer tow questions. (1) What is the genetic structure of the psr chromosome? and (2) How does it cause supercondensation of the paternal chromosomes? These studies are facilitated because (a) we have recombinant clones containing psr specific DNA which can be used as markers to characterize the chromosome by deletion analysis, (b) the gene(s) responsible for supercondensation (spc) occur in a specific region of the psr chromosome (which can be deleted) and (c) genetic experiments indicate that these genes act sometime during spermatogenesis. The following research program will be undertaken. Genetic, cytogenetic and molecular experiments will determine the structure of the psr chromosome and locate the spc gene(s) Other experiments will determine more precisely the timing of psr modification of the paternal chromosomes and search for possible target sites of psr action on the normal chromosomes. A cDNA testes library will be screened to identify psr specific transcripts and to determine if these correspond to the spc gene(s). Besides providing basic insight into mechanisms of chromosomal inactivation and the genetics of "selfish" DNA, the psr chromosome could have significant applications as a biological control agent of insects deleterious to human health and nutrition.

Psr（父性比）是一种额外的（B）染色体，在人类的生殖系统中 寄生蜂丽翅夜蛾，通过精子遗传， 然后使父本染色体凝聚成染色质团 在第一次分裂之前。父亲的染色体是 最终丢失，但psr染色体幸存下来，并被传递到 下一代通常雄性是由未受精的（单倍体） 卵，而雌性来自受精卵（二倍体）在这种黄蜂。 因此，psr的作用是将二倍体雌卵转化为单倍体卵 它们发育成PSR雄性。 该系统之所以重要，有两个原因。首先，psr是一个离散的遗传 一种引起父本染色体浓缩和失活的元件 在受精卵的有丝分裂过程中。因此，这是一个易于处理的系统 研究染色体印迹和染色体失活的遗传学。 第二，psr是“自私”遗传因素的最极端的例子， 远描述。因此，psr的遗传学研究将增加我们的 了解这些元素如何演变和发挥作用。研究将 承诺回答两个问题。(1)基因结构是什么 psr染色体（2）它是如何引起超冷凝的？ 父系染色体这些研究是便利的，因为（a）我们有 含有可用作标记的psr特异性DNA的重组克隆 通过缺失分析表征染色体，（B）基因， 负责超冷凝（SPC）发生在特定区域的 psr染色体（其可以被删除）和（c）遗传实验表明 这些基因在精子发生过程中起作用。以下 将开展研究项目。遗传、细胞遗传和分子遗传 实验将确定psr染色体的结构并定位 spc基因其他实验将更精确地确定 的psr修饰的父染色体和搜索可能的 PSR作用于正常染色体上的靶位点。睾丸cDNA文库 将被筛选以鉴定PSR特异性转录本，并确定是否 这些对应于SPC基因。 除了提供染色体失活机制的基本见解外， 和“自私”DNA的遗传学，psr染色体可能有 作为昆虫的生物控制剂的重要应用 对人体健康和营养有害。