Trans-order yolk protein can stimulate endocytic activity inDrosophilaoocytes

The first stage of follicle development was due chiefly to hydration; during the second (deutoplasmic) stage 60 mg of solid were taken up with each 100 mg increase in follicle weight. Plasma calcium and protein P rose near end of hydration stage, remained elevated during deutoplasmic stage, reached extreme levels (max. Ca = 90 mm/l.; protein P = 86 mm/l.) near ovulation, and generally fell to anestrous levels while eggs were in early cleavage. Calcium increased in proportion to protein bound P of both plasma and follicles. During deutoplasmic stage a phospho-lipoprotein, of similar gross composition to yolk protein, appeared in plasma. Liver weight increased during hydration stage, remained elevated throughout deutoplasmic stage and decreased near ovulation. Fat body weight increased with onset of estrus, reached maximum during hydration stage and progressively decreased during deutoplasmic stage. Plasma and liver changes characteristic of estrus were reproduced in fasted male snakes with estradiol injections.

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Four-way regulation of mosquito yolk protein precursor genes by juvenile hormone-, ecdysone-, nutrient-, and insulin-like peptide signaling pathways

Frontiers in Physiology ◽

10.3389/fphys.2014.00103 ◽

2014 ◽

Vol 5 ◽

Cited By ~ 66

Author(s):

Immo A. Hansen ◽

Geoffrey M. Attardo ◽

Stacy D. Rodriguez ◽

Lisa L. Drake

Keyword(s):

Juvenile Hormone ◽

Signaling Pathways ◽

Yolk Protein ◽

Protein Precursor ◽

Peptide Signaling

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α-Crystallin protein cognates in eggs of the moth, Plodia interpunctella: possible chaperones for the follicular epithelium yolk protein

Insect Biochemistry and Molecular Biology ◽

10.1016/s0965-1748(97)00111-2 ◽

1998 ◽

Vol 28 (3) ◽

pp. 151-161 ◽

Cited By ~ 16

Author(s):

Paul D Shirk ◽

Rachel Broza ◽

Miriam Hemphill ◽

O.P Perera

Keyword(s):

Plodia Interpunctella ◽

Yolk Protein ◽

Follicular Epithelium

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VIEWPOINT. An hypothesis to explain the linkage between kakapo (Strigops habroptilus) breeding and the mast fruiting of their food trees

Wildlife Research ◽

10.1071/wr07148 ◽

2008 ◽

Vol 35 (1) ◽

pp. 1 ◽

Cited By ~ 9

Author(s):

Andrew E. Fidler ◽

Stephen B. Lawrence ◽

Kenneth P. McNatty

Keyword(s):

Egg Yolk ◽

Ovarian Follicles ◽

Yolk Protein ◽

Egg Laying ◽

Food Plants ◽

Mast Seeding ◽

Future Research ◽

Yolk Protein Genes ◽

Hypothetical Mechanism ◽

Future Research Directions

An important goal in the intensive conservation management of New Zealand’s critically endangered nocturnal parrot, kakapo (Strigops habroptilus), is to increase the frequency of breeding attempts. Kakapo breeding does not occur annually but rather correlates with 3–5-year cycles in ‘mast’ seeding/fruiting of kakapo food plants, most notably podocarps such as rimu (Dacrydium cupressinum). Here we advance a hypothetical mechanism for the linking of kakapo breeding with such ‘mast’ seeding/fruiting. The essence of the hypothesis is that exposure to low levels of dietary phytochemicals may, in combination with hepatic gene ‘memory’, sensitise egg yolk protein genes, expressed in female kakapo livers, to oestrogens derived from developing ovarian follicles. Only in those years when the egg yolk protein genes have been sufficiently ‘pre-sensitised’ by dietary chemicals do kakapo ovarian follicles develop to ovulation and egg-laying occurs. While speculative, this hypothesis is both physiologically and evolutionarily plausible and suggests both future research directions and relatively simple interventions that may afford conservation workers some influence over kakapo breeding frequency.

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