Studies on the yolk nucleus of certain teleostean fishes

1966 ◽  
Vol 53 (7) ◽  
pp. 183-183 ◽  
Author(s):  
R. K. Rastogi
Keyword(s):  
Yolk Nucleus

Memoirs: On the Early Stages in the Development of Flustrella hispida (Fabricius), and on the Existence of a "Yolk Nucleus" in the Egg of this Form

1906 ◽  
Vol s2-50 (199) ◽  
pp. 435-478
Author(s):  
R. M. PACE
Keyword(s):  
Cell Lineage ◽  
Cell Stage ◽  
Single Row ◽  
Early Stages ◽  
Yolk Nucleus ◽  
Foregoing Paper

The main points in the foregoing paper maybe summarised as follows : (1) A "yolk nucleus" of the type described by Bambeke, as occurring in the egg of Pholcus, is present in the developing egg of Flustrella hispida. (2) Segmentation and cell-lineage have been followed out in detail up to the 32-cell stage. (3) The formation of the endoderm has been traced. (4) The oral and aboral ectoderm are differentiated as early as the 16-cell stage, and remain quite distinct from that time onwards. (5) The ciliated ring of the larva is formed by the coalescence of several originally distinct rows of cells, and not by the hypertrophy of a single row. (6) A stomach, comparable to that of Alcyonidium, is present also in Flustrella.

Memoirs: On the Relation of the Mitochondria and Golgi Apparatus to Yolk-Formation in the Egg-Cells of the Common Earthworm, Lumbricus Terrestris

1925 ◽  
Vol s2-69 (274) ◽  
pp. 291-316
Author(s):  
LESLIE A. HARVEY
Keyword(s):  
Golgi Apparatus ◽  
Nuclear Membrane ◽  
Lumbricus Terrestris ◽  
Yolk Formation ◽  
Central Mass ◽  
The Common ◽  
Yolk Nucleus ◽  
Earthworm Lumbricus

1. The yolk-nucleus is merely a mass of mitochondria. 2. The mitochondria arise as a cap of threads over the nucleus, and this cap grows in size and density, migrates away from the nuclear membrane and breaks up into its component mitochondrial threads. These threads become evenly spread throughout the cytoplasm of the cell. 3. The mitochondria are not clearly defined in the very young oogonia. 4. The Golgi apparatus consists of numbers of Golgi elements lying separate in the cytoplasm. There is never any attempt at concentration of these elements round one central mass. 5. The Golgi elements are probably little platelets or spheroids somewhat resembling blood corpuscles in shape. They are not rods. As fixed by Da Fano technique, each element is a little plate with a very lightly impregnating centre and a very heavily impregnating rim. 6. The Golgi elements may probably arise from the cytoplasm. 7. The nucleus contains two nucleoli; an early arising karyosome, homogeneous and solid in structure, and a plasmo some arising later This plasmosome is liquid in consistency and contains an argentophil core. The karyosome disappears before the oocyte is half grown, but the plasmosome remains in the nucleus while the egg remains in the ovary. 8. No visible nucleolar extrusions into the cytoplasm were observed. 9. Yolk probably arises from the cytoplasm; no direct metamorphosis of either mitochondria, Golgi apparatus, or nucleolus into yolk was observed.

scholarly journals Development of the Yolk Nucleus in the Oocytes of Some Fishes

Nature ◽  
1959 ◽  
Vol 184 (4700) ◽  
pp. 1746-1746 ◽  
Author(s):  
A. STOLK
Keyword(s):  
Yolk Nucleus

Aspects of the development of yolk spheres in the hen's oöcyte, studied by electron microscopy

Development ◽  
1967 ◽  
Vol 17 (2) ◽  
pp. 267-281
Author(s):  
Ruth Bellairs
Keyword(s):  
Electron Microscopy ◽  
Cell Nucleus ◽  
Raw Materials ◽  
Morphological Changes ◽  
Laying Hen ◽  
Follicle Cells ◽  
Balbiani Body ◽  
Hen’S Egg ◽  
Pass Through ◽  
Yolk Nucleus

The yolk of the hen's egg is composed mainly of proteins, lipids and water (see reviews by Bellairs, 1964; Williams, 1966). It consists essentially of yolk spheres floating in an aqueous protein medium (Grodziński, 1939; Bellairs, 1961). The raw materials from which the yolk is formed are synthesized in the liver of the laying hen and pass from there in the blood to the ovary (see reviews by Romanoff, 1960; Bellairs, 1964). Each oöcyte is enclosed in a capsule of follicle cells, and all the raw materials pass through this capsule before they enter the oöcyte. The morphological changes that take place within the oöcyte as the yolk spheres form have been described previously by light microscopists who have produced a variety of theories to explain their observations. Formerly, it was supposed that yolk arose in the so-called ‘yolk nucleus’, or Balbiani body, which lies alongside the cell nucleus, but few would subscribe to this theory now.

The Yolk-Nucleus in the Oocytes of Anabas Scandens (Teleostei)

1964 ◽  
Vol s3-105 (71) ◽  
pp. 349-352
Author(s):  
N. H. GOPAL DUTT
Keyword(s):  
Amino Acids ◽  
Circumstantial Evidence ◽  
Histochemical Tests ◽  
Sulphydryl Groups ◽  
Anabas Scandens ◽  
Yolk Nucleus ◽  
Peripheral Cytoplasm

The yolk-nucleus appears as an organelle in contact with the nucleus in the early oocyte. It is spherical and appears in fixed preparations to be composed of 3 concentric zones. Histochemical tests indicate that it contains RNA, lipid, sulphydryl groups, carbohydrate, and certain amino-acids. It assumes a reticulate form before it finally merges with the peripheral cytoplasm. Circumstantial evidence suggests that the yolk-nucleus may be involved indirectly in vitellogenesis.

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