Subcellular organization of the yolk syncytial-endoderm complex in the preimplantation yolk sac of the shark, Rhizoprionodon terraenovae

Hamlett, William C.; Schwartz, Frank J.; Didio, L. J. A.

doi:10.1007/bf00218309

Cited by 38 publications

(14 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A role for the syncytial yolk nuclei in the digestion of yolk platelets was first advanced by Beard (1888) Hamlett (1986), and Hamlett et al (1987). As shown by Hamlett et al (1987), the dictyosomes in the yolk syncytium were actively secreting and produced primary lysosomes which were supposed to fuse with the yolk platelets to bring them the necessary enzymes for self-digestion.…”

Section: Discussionmentioning

confidence: 97%

Yolk utilization in Scyliorhinus canicula, an oviparous dogfish

Lechenault

Wrisez

Mellinger

1993

The Reproduction and Development of Sharks, Skates, Rays and Ratfishes

View full text Add to dashboard Cite

SynopsisUsing plastic embedding techniques and semithin sections, in order to overcome the difficult sectioning of yolky eggs, we have been able to carry out histological study of the external yolksac from fertilization until birth in the oviparous dogfish Scyliorhinus canicula. The endoderm and its contacting giant yolk nuclei remained very flat, seemingly inactive, during the larger part of development They became activated only when the external yolksac (EYS) began to shrink. This activation increased along a vegetal-animal gradient in the EYS, but it was essentially restricted to the parts located near the yolk stalk. A statistical study of oocyte, yolk, embryo and newborn fresh and dry weights confirmed that the mass of dry tissue in the embryo (30mg) and in EYS wall (<1mg) at mid-development were still very low compared to 0.B-l.5g mass of yolk available for development. This explains why yolk weight remained practically the same during the first half of development. The end of this first period was marked by entry into the pre-hatching state at 85-115 days under laboratory conditions (14-16 D C). At this time, yolk began to enter the spiral gut, where it was digested during the second half of development and during one week period after eclosion. Eclosion occurred 170-220 days after egg laying or extraction from oviduct. Two internal storage organs were studied biometrically in the newborn: the internal yolksac (IYS), and the liver, which was fully developed at birth. Both IYS and liver dry weights corresponded to about 10% of the original yolk, while the gut was only 2 %, and the rest of the newborn body 58%. Thus, about 20% of yolk dry mass was consumed during development, a figure that is low for oviparous animals.

show abstract

Section: Discussionmentioning

confidence: 97%

Yolk utilization in Scyliorhinus canicula, an oviparous dogfish

Lechenault

Wrisez

Mellinger

1993

The Reproduction and Development of Sharks, Skates, Rays and Ratfishes

View full text Add to dashboard Cite

show abstract

“…These decreases may reflect changes in the male's contribution, providing less to fry as they approach release, or a change in utilization of the pouch fluid by the embryos, increasing intake in relation to reduced yolk reserves. In placental sharks, embryos are initially reliant on yolk reserves sequestered in the egg until maternal supplementation is activated (Hamlett et al, 1987;Hamlett et al, 1993). A comparable series of events probably transpires in pipefish.…”

Section: Table·1 Species Comparisons Of Nutrient Content Of Unfertilmentioning

confidence: 99%

Differential parental nutrient allocation in two congeneric pipefish species (Syngnathidae:Syngnathusspp.)

Ripley

Foran

2006

Journal of Experimental Biology

View full text Add to dashboard Cite

SUMMARY Male seahorses and pipefishes of the family Syngnathidae are heralded for their unique brood pouch structures for incubating embryos. There are three general types of brood pouch with increasing complexity: simple ventral gluing, two pouch flaps and a completely sealed sac. The diversity of functional roles within a type in providing nutrition, aeration and protection to offspring is unknown. Here we reveal significant differences in parental nutrient allocation to embryos for two closely related, sympatric pipefishes with similar brood pouch structure. We document differences in embryo attachment, depletion of pouch fluid nutrients over development and egg nutrient partitioning between Syngnathus floridae and Syngnathus fuscus. In S. fuscus, females produce nutritionally poor eggs and the males implant developing embryos in the brood pouch adjacent to blood vessels. A female-biased breeding population was observed, supporting the hypothesis that the cost of male parental care is high in this species. The loose connection between eggs and brood pouch tissues and the appearance of undeveloped eggs and lipid droplets in the pouch of S. floridae males suggest this species utilizes nutrient-rich eggs produced by females as nurse eggs to supplement embryonic development. A balanced sex-ratio for S. floridae further supports more equal parental contribution. This comparison provides evidence of a decline in female gametic investment and reveals the rapid diversification of syngnathid brood pouch function. Our results indicate gross classification of brooding structures into one of the three general pouch types does not predict the energetic investment of males in parental care. But rather, physiological characterization of the relative investment by each sex to offspring is essential to understanding the functional significance of the brood pouch.

show abstract

“…However, the majority of work has focused on the formation and structure of the uteroplacental interface (Gilbert and Schlemitzauer, 1966;Schlernitzauer and Gilbert, 1966;Hamlett and Wourms, 1979, 1984Hamlett et al, 1985a,b,c;Otake and Mizue, 1985;Hamlett, 1987Hamlett, , 1989bHamlett, , 1990aHamlett, ,b, 1993Hamlett et al, 1987;Otake, 1990;Hamlett et al, 1993a;Hamlett and Hysell, 1998b;Chen et al, 2001;Hamlett et al, 2005a). The main focus of the present research has been the maturational and gestational changes in the uterine mucosa, particularly the epithelium, and the degree of maternal investment in embryonic development.…”

mentioning

confidence: 94%

Gestational morphogenesis of the uterine epithelium of the gummy shark (Mustelus antarcticus)

Storrie

Walker

Laurenson

et al. 2008

Journal of Morphology

View full text Add to dashboard Cite

Developing embryos of the non-placental, viviparous gummy shark (Mustelus antarcticus) are supplied with yolk from external and internal yolk sacs throughout the initial stages of gestation. Yolk supplies are exhausted by the 7th month of an 11-12 month gestation. During embryonic development, there is an approximate 800% gain in dry mass. These factors suggest nutrients are transferred from the mother to the young. The results of the present study provide some insights into how this is occurring. The uteri are paired and both are functional. Using both light and transmission electron microscopy, regions of the uterus were examined throughout maturation and gestation. The layers of the uterine wall throughout the entire length are similar to the uteri of other chondrichthyans previously examined. The uterine epithelium of the body of the uterus is smooth contoured, does not form villi, and undergoes cyclical and secretory changes throughout maturity and gestation. In immature uteri, the epithelium is simple columnar with minimal periodic acid-Schiff-positive and Alcian blue-positive secretory vesicles. In mature uteri, the epithelium is highly stratified with cuboidal cells containing numerous Alcian blue-positive and periodic acid-Schiff-positive vesicles. With pregnancy, prominent changes include a reduction in the number of cell layers, a reduction in cell size, a reduction in the connective tissue intervening between epithelium and blood vessel endothelium, and an increase in blood vessel number and size, so that at term, the uterine compartment consists of a single layer of squamous cells immediately underlain by sinusoidal-like blood vessels. These features along with a small number of secretory vesicles, dilated intercellular spaces, and clear transport vesicles suggest the transepithelial transfer of water and minerals from the maternal to embryonic environment, supplemented by minimal uterine secretions. This is defined as minimal histotrophy and this article represents the first detailed description of this reproductive mode.

show abstract

Subcellular organization of the yolk syncytial-endoderm complex in the preimplantation yolk sac of the shark, Rhizoprionodon terraenovae

Cited by 38 publications

References 29 publications

Yolk utilization in Scyliorhinus canicula, an oviparous dogfish

Yolk utilization in Scyliorhinus canicula, an oviparous dogfish

Differential parental nutrient allocation in two congeneric pipefish species (Syngnathidae:Syngnathusspp.)

Gestational morphogenesis of the uterine epithelium of the gummy shark (Mustelus antarcticus)

Contact Info

Product

Resources

About