A Cytological Study of the Urodele Obcyte With Special Reference to the "Lambrush" Chromosome.

115 Pages·04.43 MB·English

by  Fortanella, Maria Austin

r T
FORDHAM UNIVERSITY
G raduate School of A rts and Sciences
_______February 1, 19 J>0
This dissertation prepared under my direction by
Mario A, Fontanella
entitled A Cytological^Study of the IJrodele Obcyte with Special
Reference to the "Lampbrush” Chromosome,
has been accepted in partial fulfilment of the requirements for the
Degree of
,
Charles A. Berger S,J«
(Faculty Adviser)
L
5--:

r ~i
A CYTOLOGICAL STUDY OF THE URODELE
OOCYTE WITH SPECIAL REFERENCE TO
THE "LAMPBRUSH" CHROMOSOME
BY
MARIO AUSTIN FONTANELLA
B.S., New York University, *37
M.A., Columbia University, *40
DISSERTATION
SUBMITTED IN PARTIAL FULFILLMENT OF THE
REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY
IN THE DEPARTMENT OF BIOLOGY AT
FORDHAM UNIVERSITY
NEW YORK
1950
L _l
ProQuest Number: 10992991
All rights reserved
INFORMATION TO ALL USERS
The quality of this reproduction is dependent upon the quality of the copy submitted.
In the unlikely event that the author did not send a complete manuscript
and there are missing pages, these will be noted. Also, if material had to be removed,
a note will indicate the deletion.
uest
ProQuest 10992991
Published by ProQuest LLC(2018). Copyright of the Dissertation is held by the Author.
All rights reserved.
This work is protected against unauthorized copying under Title 17, United States Code
Microform Edition © ProQuest LLC.
ProQuest LLC.
789 East Eisenhower Parkway
P.O. Box 1346
Ann Arbor, Ml 48106- 1346
TABLE OF CONTENTS
Page
LIST OF TABLES .............................. iv
LIST OF FIGURES ............................. v
ACKNOWLEDGEMENT ............................. ix
I. INTRODUCTION........................... 1
II. MATERIAL AND METHODS .................... 5
III. OBSERVATIONS AND RESULTS ................ 8
Origin of the germ cells ................ 8
Larva ............................... 8
Adult ............................ 8
The membranes .......................... 9
Structure of the oocyte ................. 10
Cytoplasm and yolk..................... 13
The nucleoli ........................... 16
The chromosomes ................... 39
Premeiotic resting stage ............. 39
Preleptotene stages ................. 40
Leptotene stage ..................... 40
Zygotene stage ......... 41
Pachytene stage ................ 41
Diplotene stage ................ 42
Early "lampbrush” stage .............. 43
Continuous "lampbrush" stage ......... 44
Discontinuous "lampbrush" stage ...... 44
Reappearance of meiotic bivalents ..... 45
IV. DISCUSSION ............................. 77
Cytoplasm and yolk ..................... 77
The nucleoli ......... 81
The spirallization cycle ................ 83
The "lampbrush" as a polyploid structure .. 85
General considerations ............. 89
V. SUMMARY ................................ 93
BIBLIOGRAPHY 96
r
A CYTOLOGICAL STUDY OF THE URODELE
OOCYTE WITH SPECIAL REFERENCE TO
THE "LAMPBRUSH" CHROMOSOME
L
iv
r “i
LIST OF TABLES
Table Page
I, Measurement of the diameters of
serial sections of one oocyte and
its germinal vesicle. Eft stage
of Triturus viridescens viridescens .... 18
II. Correlation of -prophasic progress
with the growth of the germinal
vesicle and oocyte. Necturus
maculosus maculosus ...... 48
L _l
V
r i
LIST OF FIGURES
Figure Page
!• Triturus viridescens viridescens.
Genital ridge of 1 cm. larva .............. 20
2. Desmognathus fuscus fuscus. Genital
ridge of 2.5 cm. larva .................... 20
3. Desmognathus fuscus fuscus. Cyst of
oogonia and o8cytes in the cyst wall
epithelium ............................... 22
4. Desmognathus fuscus fuscus. Cyst of
oogonia and oocytes, showing telophase
of last mitotic division before meiosis .... 22
5. Desmognathus fuscus fuscus. Portion of
a cyst containing cells in different
stages of development .................... 24
6. Necturus maculosus maculosus. Portion of
a cyst containing cells in different
stases of development ................... 24
Triturus viridescens viridescens. A
cyst of obcytes in the eft stage ......... 26
Triturus viridescens viridescens. Part
of a cyst of the eft stase to show the
vitelline areas ......................... 26
Necturus maculosus maculosus. Late
oocyte stained with Feulgen-reaction ..... 28
1°* Triturus viridescens viridescens.
Section of large obcyte to show peri­
pheral migration of germinal vesicle ..... 28
11* Triturus viridescens viridescens. An
isolated section showing large baso-
philic bodies in the cytoplasm ........... 30
12. Triturus viridescens viridescens.
Vitelline areas in adjacent o&cytes ...... 30
13. Triturus viridescens viridescens.
Large obcyte to show depos it ion of yolk .... 32
l _i
Figure Page
14. Desmognathus fuscus fuscus. Section
showing degenerative changes in large
oocyte ................................ 32
15. Desmognathus fuscus fuscus. Section to
show the role of follicular cells in a
degenerating oocyte .................... 34
16. Desmognathus fuscus fuscus. Section to
show the role of follicular cells in a
degenerating oocyte ............... 34
17. Triturus viridescens viridescens♦ Section
to show structure of germinal vesicle,
cytoplasm, and yolk spherule ......... 36
18. Necturus maculosus maculosus. Section
of whole obcyte showing nucleoli in
the cvtoplasm ........................ 36
I9* Necturus maculosus maculosus. Section to
show nucleoli andlampbrush" loops stained
with methyl-green-pyronine .............. 38
20 • Triturus viridescens viridescens. Over­
destained nucleoli in the eft stage ..... 38
21. Necturus maculosus maculosus. Oogonial
resting stage .......................... 50
22. Necturus maculosus maculosus. Early
preleptotene stage ............... 50
23. Necturus maculosus maculosus. A later
preleptotene stage ..................... 52
24. Necturus maculosus maculosus.
Leptotene stage ........................ 52
25. Necturus maculosus maculosus. Zygotene
stage ................................ 54
25. Necturus maculosus maculosus. Pachytene
stage ................................. 54
27. Necturus maculosus maculosus. Early
diplotene stage characterized by the
opening-out of bivalents ............... 56
vii
r n
Figure Page
28. Necturus maculosus maculosus. Later
diplotene stage with chromosomes
that are beginning to show the
"lampbrush” characteristics .............. 56
29. Necturus maculosus maculosus. Section
of whole nucleus in the continuous
”lampbrush” stage ....................... 58
3°* Necturus maculosus maculosus. The
continuous "lampbrush” stage showing
the structure with a definite central
thread or "backbone” ..................... 58
31. Necturus maculosus maculosus. Section
of whole nucleus in the discontinuous
"lampbrush” stage ....................... 60
32. Necturus maculosus maculosus. The
discontinuous "lampbrush" stage showing
series of side-loops attached to
discrete chromomeres ................... 60
33. Necturus maculosus maculosus. Cross-
sectional view of the "larapbrush"
structure ........................... 62
34. Necturus maculosus maculosus. Section
of whole nucleus showing disintegration
of "lampbrush" structures and reappearance
of bivalents .... 62
35. Necturus maculosus maculosus. Section
to show a conventional bivalent that has
appeared among the disintegrating "lamp­
brush" structures .................. 64
33. Necturus maculosus maculosus. Section
to show newly-appeared bivalent .......... 64
37. Necturus maculosus maculosus. Section
to show condensed nucleolare xudates ...... 66
38. Necturus maculosus maculosus. Section
to show newly-appeared bivalent in a
stage of greater condensation than in
previous figures ....................... 66
L -I