title: Characterization of hemocytes proliferation in larval silkworm, Bombyx mori.
abstract: Hemocytes play multiple important roles during insect growth and development. Five types of hemocytes have been identified in the silkworm, Bombyx mori: prohemocyte, plasmatocyte, granulocyte, spherulocyte, and oenocytoid. We used the S-phase marker bromodeoxyuridine (BrdU) antibody along with the mitosis marker phosphohistone H3 (PHH3) antibody to monitor proliferation of hemocytes in vivo. The results indicate that silkworm hematopoiesis not only occurs in the circulatory system but also in hematopoietic organs (HPOs). During the 5th instar, the hemocyte proliferation in the circulatory system reaches a peak at the pre-wandering stage. Following infection by Escherichia coli, circulating hemocytes increase their cell divisions as demanded by the cellular immune response. All hemocytes, except spherulocytes, have the capacity to multiply in vivo. The BrdU label-retaining assay shows that a small portion of cells from the circulatory system and the HPOs are continuously labelled up to 9days and 4days respectively. A small number of long-term label retaining cells (LRCs) quiescently locate in circulatory system. All results indicate that there are a few quiescent stem cells or some progenitors in the larval circulatory system and HPO that produce new hemocytes and continuously release them into the circulating system.
authors.affiliation: State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400716, China. libytan163com@163.com
authors.forename: Juan
authors.initials: J
authors.lastname: Tan
authors.forename: Man
authors.initials: M
authors.lastname: Xu
authors.forename: Kui
authors.initials: K
authors.lastname: Zhang
authors.forename: Xue
authors.initials: X
authors.lastname: Wang
authors.forename: Siyuan
authors.initials: S
authors.lastname: Chen
authors.forename: Tai
authors.initials: T
authors.lastname: Li
authors.forename: Zhonghuai
authors.initials: Z
authors.lastname: Xiang
authors.forename: Hongjuan
authors.initials: H
authors.lastname: Cui
mesh_terms: D000818:Animals; D012831:Bombyx / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism / Q000382:microbiology; D049109:Cell Proliferation; D004926:Escherichia coli / Q000502:physiology; D006434:Hemocytes / Q000166:cytology* / Q000378:metabolism / Q000382:microbiology; D006657:Histones / Q000378:metabolism; D019476:Insect Proteins / Q000378:metabolism; D007814:Larva / Q000166:cytology* / Q000254:growth & development / Q000378:metabolism / Q000382:microbiology
chemical_list: D006657:Histones; D019476:Insect Proteins