This paper reports the G-band patterns of the metaphase chromosomes of tonguefish Cynoglossus semilaevis Gu¨nther, 1873, the first description and numbering of the karyotyped bands in metaphase chromosomes. The G-banding method stained positively 68.1% of the chromosome surface in C. semilaevis; a total of 171 G-bands (89 positive, 74 negative and eight variables) were recorded in 20 pairs of autosomes and in one pair of the sex-chromosomes Z and W.
Abstract Liang, Y.J. and Zhang, S.C. 2006. Demonstration of plasminogen-like protein in amphioxus with implications for the origin of vertebrate liver. -Acta Zoologica (Stockholm) 87 : 141-145Plasminogen, the proenzyme of serine protease plasmin, is a plasma glycoprotein synthesized primarily in the liver, and its evolutionary origin in chordates remains unclear. We demonstrated here that the humoral fluid in amphioxus is capable of cross-reacting with anti-human or anti-mouse plasminogen antibodies, and the hepatic diverticulum in amphioxus is the site of plasminogen-like protein synthesis. The presence of plasminogen-like protein in amphioxus pushes the origin of plasminogen to before the last common ancestor of vertebrates. In addition, the localization of plasminogen-like protein in the hepatic diverticulum suggests that the diverticulum in amphioxus is functionally homologous to the vertebrate liver in respect of plasminogen synthesis, supporting the hypothesis that the vertebrate liver evolved from the hepatic diverticulum of an amphioxus-like ancestor during early chordate evolution.
In this study, bioinformatics analysis, tissue distribution and developmental expression pattern of lipoprotein lipase (lpl) and hepatic lipase (lipc) in zebrafish Danio rerio are reported. In adult D. rerio, lpl was highly expressed in liver. This is remarkably different from the tissue expression pattern of LPL in mammals, which is not detected in the adult liver. The expression of lipc was liver specific, which is consistent with that in mammals. During embryogenesis, lpl mRNA was increased gradually in concentration from 0.5 hpf (hour post fertilization) to 6 dpf (days post fertilization), but lipc was not expressed at the early stage of the embryo until 3 dpf. In situ hybridization further displayed the expression pattern of lpl mainly restricted to the head region including cells surrounding the mouth opening, branchial arches, pectoral fin and lateral line neuromast, whereas lipc was mainly restricted to the liver and part of head regions including lens. This lays a foundation for further investigation of lpl or lipc function and evolution in fishes.
This study provides the first detailed table of normal development of the rosy barb embryo, from fertilization to post-hatching. We define six broad periods of embryogenesis, i.e. the zygote, cleavage, blastula, gastrula, segmentation and larval periods. These divisions highlight the changing spectrum of major developmental processes occurring during these periods. Stages that subdivide the periods are named, not numbered as in most other series. The stages and their names are based on morphological features usually readily identified by examination of the live embryo under a stereomicroscope. These provide a detailed embryological staging by morphological criteria for future studies on molecular biology and biotechnology in this species.
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