Resumo
In the present paper the behaviour of the chromosomes in the spermatogenesis of the Myriapod Rhinocricus Padbergi Verhoeff, 1938 is studied. The primary spermatocytes are provided with 10 independent bivalents which separate normally giving rise to equivalent secondary spermatocytes. No indication of sex chromosomes has been found. Fusion of two bivalents or of four, two by two, has been observed, giving origin to secondary spermatocytes with 9 and 8 chromosomes respectively, in which fused chromosomes could be discovered. For analysing the facts the chomosomes of both, primary and secondary metaphases were separately counted from a total of 190 celis of four individuals and statistically treted. The X2-test gave insignificant results. Twenty chomosomes were counted in somatic tissues. The heterochròmatic parts of the leptotene threads were usually arranged in the periphery of the nucleus. In resting nuclei chromocenters can be observed in varyng number. Their chromosomal nature is revealed by the fact that when treated by KCÑ or KNOS they begin uncoiling.
Meiose em Rhinocricus Padbergi Verhoeff, 1938
Yone G.P. de Castro
Da Cadeira de Zoologia, Anatomia e Fisiología da Escola Superior de Agricultura "Luiz de Queirós" da Universidade de S. Paulo
SUMMARY
In the present paper the behaviour of the chromosomes in the spermatogenesis of the Myriapod Rhinocricus Padbergi Verhoeff, 1938 is studied.
The primary spermatocytes are provided with 10 independent bivalents which separate normally giving rise to equivalent secondary spermatocytes. No indication of sex chromosomes has been found. Fusion of two bivalents or of four, two by two, has been observed, giving origin to secondary spermatocytes with 9 and 8 chromosomes respectively, in which fused chromosomes could be discovered.
For analysing the facts the chomosomes of both, primary and secondary metaphases were separately counted from a total of 190 celis of four individuals and statistically treted. The X2-test gave insignificant results.
Twenty chomosomes were counted in somatic tissues.
The heterochròmatic parts of the leptotene threads were usually arranged in the periphery of the nucleus.
In resting nuclei chromocenters can be observed in varyng number. Their chromosomal nature is revealed by the fact that when treated by KCÑ or KNOS they begin uncoiling.
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LITERATURA
BRIEGER, F. G. - 1937. Tábuas e Fórmulas para Estatística. Cia. Melhoramentos de S. Paulo - S. Paulo.
BRIEGER, F. G. - 1939. Estrutura dos cromossomios na meiose. Jornal de Agronomia, 2: n° 2.
BÜCHERL, WOLFGANG - 1939. Os Quilopodos do Brasil. Memorias do Instituto Butantan. Vol. XIII.
FEDERLEY, HARRY - 1932. The Conjugation of the Chromosomes. Sixth International Congress of Genetics..... 1: 153-164.
FEDERLEY, HARRY - 1937. Fusion zweier Chromosomen als Folge Einer Kreuzung. Acta Soc. pro Fauna et Flora Fenn 60.
FEDERLEY, HARRY - 1938. Chromosomenzahlen Finnlan-discher Lepidopteren. 1 - Rhopalocera. Hereditas XXIV.
FEDERLEY, HARRY - 1943. Zytologische Untersuchungen An Mischiligen Gattung. Dicranura b. (Lepidoptera). Hereditas 29
MORGAN, D. T. JR - 1943. The Formation of Chromocenters in Interkinetic Nuclei of Maize. Journal of Heredity XXXIV n. 7.
OETTINGER, R. - 1908. Zur Kenntnis der Spermatogenese bei den Myriapoden. Samenreifung und Samenbildung von Pachylulus varius Fabr. Zool. Anz. 33.
OETTINGER, R. - 1909. Zur Kenntnis der Spermatogenese bei den Myriapoden. Samenreifung und Samenbildung Pachylulus varius Fabr. Arch. Zellf. 3 (Citado por Schva-der, 1928).
OURA, G. - 1936. A New Method of Unravelling the Chromonema Spirals. Zeitschrift für wisseschaftlichs- Mikros-kop?e und für mikroskopische Thechnik 53 536-537.
SCHRADER, F. - 1928. Die Geschlechtschromosomen. Gebrü-der Borntraeger - Berlin.
SEILER, J. e HANIEL, C. B. - 1921. Das verschiedene Verhal-ten der Chromosomen in Eireifung und Samenreifung von Lymantria monacha L. Z. f. ind. Abst. und Vbgs-lehre. XXVn: 81-103.
SOKOLOFF, J. - 1914. über die Spermatogenese bei Poly-xenus sp. Zool. Anz. XLTV.
WHITE, M. J. D. - 1945. Animal Cytology and Evolution. University Press, Cambridge. 375 pags.
- BRIEGER, F. G. - 1937. Tábuas e Fórmulas para Estatística. Cia. Melhoramentos de S. Paulo - S. Paulo.
- BRIEGER, F. G. - 1939. Estrutura dos cromossomios na meiose. Jornal de Agronomia, 2: n° 2.
- BÜCHERL, WOLFGANG - 1939. Os Quilopodos do Brasil. Memorias do Instituto Butantan. Vol. XIII.
- FEDERLEY, HARRY - 1932. The Conjugation of the Chromosomes. Sixth International Congress of Genetics..... 1: 153-164.
- FEDERLEY, HARRY - 1937. Fusion zweier Chromosomen als Folge Einer Kreuzung. Acta Soc. pro Fauna et Flora Fenn 60.
- FEDERLEY, HARRY - 1938. Chromosomenzahlen Finnlan-discher Lepidopteren. 1 - Rhopalocera. Hereditas XXIV.
- FEDERLEY, HARRY - 1943. Zytologische Untersuchungen An Mischiligen Gattung. Dicranura b. (Lepidoptera). Hereditas 29
- MORGAN, D. T. JR - 1943. The Formation of Chromocenters in Interkinetic Nuclei of Maize. Journal of Heredity XXXIV n. 7.
- OETTINGER, R. - 1908. Zur Kenntnis der Spermatogenese bei den Myriapoden. Samenreifung und Samenbildung von Pachylulus varius Fabr. Zool. Anz. 33.
- OETTINGER, R. - 1909. Zur Kenntnis der Spermatogenese bei den Myriapoden. Samenreifung und Samenbildung Pachylulus varius Fabr. Arch. Zellf. 3 (Citado por Schva-der, 1928).
- OURA, G. - 1936. A New Method of Unravelling the Chromonema Spirals Zeitschrift für wisseschaftlichs- Mikros-kop?e und für mikroskopische Thechnik 53 536-537.
- SCHRADER, F. - 1928. Die Geschlechtschromosomen. Gebrü-der Borntraeger - Berlin.
- SEILER, J. e HANIEL, C. B. - 1921. Das verschiedene Verhal-ten der Chromosomen in Eireifung und Samenreifung von Lymantria monacha L. Z. f. ind. Abst. und Vbgs-lehre. XXVn: 81-103.
- SOKOLOFF, J. - 1914. über die Spermatogenese bei Poly-xenus sp. Zool. Anz. XLTV.
- WHITE, M. J. D. - 1945. Animal Cytology and Evolution. University Press, Cambridge. 375 pags.
Datas de Publicação
-
Publicação nesta coleção
05 Fev 2013 -
Data do Fascículo
1948
