L'évolution de la formule chromosomiale chez les Vertébrés

Matthey, R

doi:10.1007/bf02156807

Cited by 41 publications

(34 citation statements)

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“…For each, chromosomal com ponents of 50 to 100 cells were counted and evaluated. Arm-ratio (AR) and fundamental number (FN; the total of major chromo somal arms) were calculated following Levan et al, 1964, andMatthey, 1945, respectively. Karyograms were prepared from enlarged prints of photographs taken at 1000X.…”

Section: Resultsmentioning

confidence: 99%

Reproductive anatomy and gametogenesis inShipleya inermis(Cestoda: Dioecocestidae)

Rausch

1990

Ann. Parasitol. Hum. Comp.

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Study of the reproductive anatomy in 65 strobilae of the dioe cious cestode Shipleya inermis Fuhrmann, 1908 (Acoleata: Dioe cocestidae) showed that a common genital duct, probably arising through fusion of the vas deferens and the proximal portion of the vaginal duct, compensated functionally for the loss of a patent vagina. Gonochorism was characteristic, but rudimentary genital organs of the opposite sex were present in 26 % of males and 9 % of females; two strobilae (3 %) were hermaphroditic. Her maphrodites had normally developed male organs and were capable of cross-fertilization as males; their female organs were much reduced in size but were functional, and eggs or fertilized ova in the uteri indicated that self-fertilization occurred. Gametoge nesis was traced, mainly in chromosomal preparations. The diploid chromosomal complement in embryos and germ-line cells consisted of four pairs of homologues (2n = 8, n = 4, FN = 14). Based on observation in female cestodes of one pair of chromosomes having non-homologous or non-pairing segments due to influence of heterochromatin, the authors suggest that females produce gametes of two types relative to heterochromatic DNA, while males are homogametic, and that sex-determining effects are associated therein. In males, meiosis included chromosomal pairing and recom bination, after which heterochromatin was eliminated from germ line cells through fragmentation. Other biological characteristics of S. inermis in the hosts, Limnodromus spp. (Charadriiformes), are briefly discussed. The genera of dioecious cestodes in the order Cyclophyllidea have been arranged in either one or two families in the suborder Acoleata Skriabin, 1940. In a recent revision of the Acoleata, Ryzhikov and Tolkacheva (1981) Accepté le : 27 décembre 1990.Une étude a été faite sur 65 strobiles du cestode dioïque Shi pleya inermis Fuhrmann, 1908 (Acoleata : Dioecocestidae) concer nant l'anatomie reproductrice et la gamétogenèse. Elle a montré que le conduit génital commun (résultant vraisemblablement de la fusion du canal déférent et de la partie proximale du conduit vaginal) sert à compenser la perte d'un vagin séparé. Chez ce ces tode, le gonochorisme est typique, mais les auteurs ont observé des organes génitaux rudimentaires de l'autre sexe dans 26 % des mâles et dans 9 % des femelles. Deux des 65 strobiles (3 %) sont hermaphrodites, avec l'appareil mâle fonctionnel et capable de fécondation réciproque; les organes femelles sont réduits en taille. Les oeufs des spécimens hermaphrodites ont atteint la maturité après autofécondation. La gamétogenèse a été observée principa lement dans des préparations chromosomiques. La garniture chro-

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Section: Resultsmentioning

confidence: 99%

Reproductive anatomy and gametogenesis inShipleya inermis(Cestoda: Dioecocestidae)

Rausch

1990

Ann. Parasitol. Hum. Comp.

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“…Infatti il numero di braccia autosomiche (*) e uguale a 50 in tutte e quattro le specie delle quali disponiamo di personali dati morfologici e cariometrici (Miniopterus schreibersi} Pipistrellus kuhli, P. savii e Barbastella barbastellus); a rendere maggiormente fondata l'ipotesi robertsoniana (ROBERTSON 1916) nell'evoluzione del cariotipo dei * Preferiamo effettuare il computo ed il confronto delle sole braccia autosomiche e non di tutti i cromosomi, come nel numero fondamentale (MATTHEY 1945), poiche lavorando su cromosomi somatici, e non su materiale testicolare, avremmo l'inconveniente di numeri fondamentali differenti se computati su linee cellulari maschili o femminili della stessa specie. Vespertilionidi, stanno le osservazioni di BovEY (1949) Tuttavia l'identificazione nelle braccia autosomiche dei grandi cromosomi metacentrici di Barbastella barbastellus, dei cromosomi acrocentrici delle due specie del genere Pipistrellus e di Miniopterus si puo tentare solo in linea puramente ipotetica, basandosi sui soli dati cariometrici.…”

Section: Descrizione E Discussion£ Dei Risultatiunclassified

I Cromosomi diBarbastella Barbastellus(Mammalia — Chiroptera)

Capanna¹,

Conti²,

Renzis³

1968

Caryologia

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“…These near the diploid number considered as primitive for fishes, according to the theory of Ohno (1970), Ohno and Atkin (1966) and Ohno et al (1967), and for mammals (Matthey 1945(Matthey , 1962(Matthey ,1973. Nevertheless, the structure of both karyotypes differs in the fundamental number.…”

Section: Methodsmentioning

confidence: 98%