Development of the anal vesicle, salivary glands and gut in the egg-larval parasitoid Chelonus inanitus: tools to take up nutrients and to manipulate the host?

Larvae of endoparasitoids undergo extensive morphological changes and often have special features to allow their development inside the host. We present the first detailed study on the development of the anal vesicle and the gut. The analyses reveal that the anal vesicle is first seen on the dorsal side of the abdomen as an internal structure covered by a membrane.

Stage-dependent strategies of host invasion in the egg-larval parasitoid Chelonus inanitus.

Chelonus inanitus (Braconidae) is a solitary egg-larval parasitoid which lays its eggs into eggs of Spodoptera littoralis (Noctuidae); the parasitoid larva then develops in the haemocoel of the host larva. Host embryonic development lasts approx. 3.

Ovary development and polydnavirus morphogenesis in the parasitic wasp Chelonus inanitus. II. Ultrastructural analysis of calyx cell development, virion formation and release.

Polydnaviruses are unique symbiotic viruses that are formed only in calyx cells in the ovary of parasitic wasps in the families Braconidae and Ichneumonidae; accordingly, two genera, Bracovirus and Ichnovirus are recognized. We have presented a detailed ultrastructural analysis of ovary and calyx cell differentiation and virion morphogenesis, together with the first data on virion release in a bracovirus. Differentiation of the ovary into germarium/vitellarium and the calyx region begins immediately after pupation.

Ovary development and polydnavirus morphogenesis in the parasitic wasp Chelonus inanitus. I. Ovary morphogenesis, amplification of viral DNA and ecdysteroid titres.

Polydnaviruses are unique symbiotic viruses that are replicated in the calyx cells of the ovary of some parasitic wasps. They have a segmented genome of circular double-stranded DNA and are injected along with the wasp's egg into the host, where they are essential for successful parasitism. Polydnaviruses replicate from integrated proviral DNA, and after excision of viral segments, flanking DNA is rejoined.

The metamorphic switch in hemoglobin phenotype ofXenopus laevis involves erythroid cell replacement.

To elucidate the cellular basis of hemoglobin transition inXenopus laevis the distribution of larval and adult hemoglobins was analyzed by indirect immunofluorescence in the circulating erythrocytes during metamorphosis. In addition, the morphological characteristics as well as the capacity for synthesis of DNA and hemoglobin in the erythrocytes were followed during the same developmental period. Our quantitative analysis on the distribution of larval and adult hemoglobins suggests that they are localized in different cells.