we investigate evolutionary changes when genome regions become completely sex-linked, by analyses of multiple species of flatworms (Platyhelminthes; among which schistosomes recently evolved gonochorism from ancestral hermaphroditism), and roundworms (Nematoda) ...
The present communication reports the ultra structural abnormalities in sperm of a fish species Cyprinus carpio inhabiting a polluted lake, Umiam in North... CJ Herrera Fernández,S Prieto,P Chavarriaga Aguirre,... - 《Microscopy Research & Technique》 被引量: 1发表: 2004年 加载更多来源...
Further, the frequency distributions of sizes among fish lineages resemble those of most other animal taxa, in being right-skewed, even on a log scale. Using an approach that measures rates of size evolution (in darwins) within a formal phylogenetic framework, we interpret the shape of size ...
Through a progeny test of sex-reversed fish and a linkage analysis of isolated sex-linked DNA markers, we show that O. hubbsi, which is one of the most closely related species to O. dancena, has a ZZ/ZW system. In addition, genetic and fluorescence in situ hybridization mapping of the...
Sex determination systems are highly variable in many taxa, sometimes even between closely related species. Yet the number and direction of transitions between these systems have seldom been characterized, and the underlying mechanisms are still poorly u
Evolution, theory in biology postulating that the various types of living things on Earth have their origin in other preexisting types and that the distinguishable differences are due to modifications in successive generations. The theory of evolution is
. Alternative models account for the possibility that all cases of sex change require stimulation from smaller conspecifics (universal induction-inhibition model) or that all fish have the genetic capacity to switch mechanisms, depending on changing ecological conditions and resulting changes in mating ...
Environmental sex determination: interaction of temperature and genotype in a fish. Sex determination in an atherinid fish, the Atlantic silverside (Menidia menidia), is under the control of both genotype and temperature during a specific period of larval development. The sex ratios of the progeny...
Teleost fish exhibit a remarkable diversity in the control of sex determination, offering the opportunity to identify novel differentiation mechanisms and their ecological consequences. Here, we perform GWAS using 4715 fish and 46,501 SNP to map sex dete
The emergence of fish from the sea was one of the key moments that transformed the evolution of life on Earth. 海洋鱼类在陆上出现是地球生物进化史上的重要时刻之一。 www.joyen.net 2. Some scientists suggested that there had been a gradual evolution of life on earth. 一些科学家认为,地球上的...