Dataset Information

Two hemocyte lineages exist in silkworm larval hematopoietic organ.

ABSTRACT:

Background

Insects have multiple hemocyte morphotypes with different functions as do vertebrates, however, their hematopoietic lineages are largely unexplored with the exception of Drosophila melanogaster.

Methodology/principal findings

To study the hematopoietic lineage of the silkworm, Bombyx mori, we investigated in vivo and in vitro differentiation of hemocyte precursors in the hematopoietic organ (HPO) into the four mature hemocyte subsets, namely, plasmatocytes, granulocytes, oenocytoids, and spherulocytes. Five days after implantation of enzymatically-dispersed HPO cells from a GFP-expressing transgenic line into the hemocoel of normal larvae, differentiation into plasmatocytes, granulocytes and oenocytoids, but not spherulocytes, was observed. When the HPO cells were cultured in vitro, plasmatocytes appeared rapidly, and oenocytoids possessing prophenol oxidase activity appeared several days later. HPO cells were also able to differentiate into a small number of granulocytes, but not into spherulocytes. When functionally mature plasmatocytes were cultured in vitro, oenocytoids were observed 10 days later. These results suggest that the hemocyte precursors in HPO first differentiate into plasmatocytes, which further change into oenocytoids.

Conclusions/significance

From these results, we propose that B. mori hemocytes can be divided into two major lineages, a granulocyte lineage and a plasmatocyte-oenocytoid lineage. The origins of the spherulocytes could not be determined in this study. We construct a model for the hematopoietic lineages at the larval stage of B. mori.

SUBMITTER: Nakahara Y

PROVIDER: S-EPMC2911379 | biostudies-literature | 2010 Jul

REPOSITORIES: biostudies-literature

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Publications

Two hemocyte lineages exist in silkworm larval hematopoietic organ.

Nakahara Yuichi Y Kanamori Yasushi Y Kiuchi Makoto M Kamimura Manabu M

PloS one 20100728 7

<h4>Background</h4>Insects have multiple hemocyte morphotypes with different functions as do vertebrates, however, their hematopoietic lineages are largely unexplored with the exception of Drosophila melanogaster.<h4>Methodology/principal findings</h4>To study the hematopoietic lineage of the silkworm, Bombyx mori, we investigated in vivo and in vitro differentiation of hemocyte precursors in the hematopoietic organ (HPO) into the four mature hemocyte subsets, namely, plasmatocytes, granulocytes ...[more]

PMID: 20676370

Similar Datasets

Project description:BackgroundTransglutaminases (TGases) form a group of enzymes that have many different substrates and among the most well known are fibrin for Factor XIIIa and the clotting protein in crustaceans. We also found that TGase is an abundant protein in the hematopoietic tissue (Hpt) cells of crayfish and hence we have studied the possible function of this enzyme in hematopoiesis.ResultsTGase is one of the most abundant proteins in the Hpt and its mRNA expression as well as enzyme activity is very high in the Hpt cells, lesser in the semi-granular hemocytes and very low in the granular cells. In cultured hematopoietic tissues, high activity was present in cells in the centre of the tissue, whereas cells migrating out of the tissue had very low TGase activity. RNAi experiments using dsRNA for TGase completely knocked down the transcript and as a result the cell morphology was changed and the cells started to spread intensely. If astakine, a cytokine directly involved in hematopoiesis, was added the cells started to spread and adopt a morphology similar to that observed after RNAi of TGase. Astakine had no effect on TGase expression, but after a prolonged incubation for one week with this invertebrate cytokine, TGase activity inside and outside the cells was completely lost. Thus it seems as if astakine addition to the Hpt cells and RNAi of TGase in the cell culture will lead to the same results, i.e. loss of TGase activity in the cells and they start to differentiate and spread.ConclusionThe results of this study suggest that TGase is important for keeping the Hpt cells in an undifferentiated stage inside the hematopoietic tissue and if expression of TGase mRNA is blocked the cells start to differentiate and spread. This shows a new function for transglutaminase in preventing hematopoietic stem cells from starting to differentiate and migrate into the hemolymph, whereas their proliferation is unaffected. Astakine is also important for the hematopoiesis, since it induces hemocyte synthesis in the Hpt but now we also show that it in some unknown way participates in the differentiation of the Hpt cells.

Dataset Information

Two hemocyte lineages exist in silkworm larval hematopoietic organ.

Background

Methodology/principal findings

Conclusions/significance

Publications

Two hemocyte lineages exist in silkworm larval hematopoietic organ.

Similar Datasets

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