Cytogenetic And Methodology Studies On Hylyphantes Graminicola

This article reported the cytogenetic and methodologystudies on Hylyphantes graminicola (Araneae: Linyphiidae). Theauthor initiated an improved needle smear method from threeaspects of materials, methods and technology for thepreparations of small spiders. The procedure was as follows:using 3-7d embryo cells as the analyzing material of thekaryotype for mitosis and new matured spider sex gland formeiosis. After living without food and water for 2-3d (25℃), thespider was fed on the sponge soaked with 0.01% colchicinessolution for 5d, and then was used for anaesthesia,microscopical anatomy, material(aex gland or embryo)separation, marking, tissue crumbing(with needle), infiltration,stationary, coloration, microscopical examination, photographyand calculation. In addition, corresponding methods were usedin C-band and N-band stain, and SC_s were stained using 60% silvernitrate solution. At last, we got some cytogenetic conclusionsof the spider:(1) By use of observing and analyzing the mitosis ofHylyphantes graminicola's embryo cells, we found there were two kinds of somatic cell karyotypes, i. e., the amounts of thefemale and male's chromosomes were different from eachother: the female(♀) 2n=26, the male (♂) 2n=24. Most of theirchromosomes were telocentric or subtelocentric chromosome, anda few of them had some obvious secondary constriction. Thesituation of the heterochromatin on the C-band was not verystable. Sex chromosomes' type was X₁X₂O, the female (♀): 2n=26(22+X₁X₁X₂X₂), the male (♂): 2n=24 (22+X₁X₂), the number of thefemale chromosomes was more than that of the male with two Xchromosomes, and each doubles of the sex chromosomes were equalin length. In summary, chromosome polymorphism in Hylyphantosgraminicola embryo cells were represented obviously;Moreover, haploid, diploid and haploid-diploid mixoploidy ordisappearing B-chromosomes appeared accidentlly.(2) Through observing and analyzing the meiosis ofHylyphantes graminicola's spermary cells, the leptotenegcould not be discerned clearly, although each chromosomes hadalready duplicated into two chromatids. When moved intozygotene, the configuration of the chromosomes had not changeda lot, only the homologous chromosomes started to get in pairs.Some overlappings were discovered in pachytene, and theconfiguration of its chromosomes were different from zygotene,...