Skip to main content
Fig. 6 | BMC Developmental Biology

Fig. 6

From: Vitellogenins in the spider Parasteatoda tepidariorum – expression profile and putative hormonal regulation of vitellogenesis

Fig. 6

Hypothetical model of vitellogenesis and its hormonal control in P. tepidariorum spiders. a Organs and tissues responsible for the synthesis and transport of the Vg with a crucial role the midgut glands and ovaries. b The probable role of hormones in the vitellogenesis. Heterosynthesis of the Vg in the midgut glands is probably under control of the juvenile hormone and ecdysteroids (indicated by green arrows). On the other hand, the juvenile hormone may be only one hormone that is responsible for the control of the Vg autosynthesis in the ovaries. The Vg secretion from the midgut glands into the hemolymph (indicated by a blue arrow) is probably controlled by ecdysteroids. The Vg uptake by oocytes (indicated by a black arrow) may be regulated by the juvenile hormone and ecdysteroids. It should be remembered about the possible priming effect (indicated by dashed arrows) induced by the juvenile hormone. As literature data indicate the one hormone can affect the metabolism of the other hormone. Thus this possible action of hormones in P. tepidariorum is indicated by an arrow with two caves

Back to article page