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1

Genetic mechanisms underlying male sex determination in mammals

100%

Piprek R. P.

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tom 50

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nr 4

347-360

EN

Genetic control of gonadal development proceeds through either the male or female molecular pathways, driving bipotential gonadal anlage differentiation into a testis or ovary. Antagonistic interactions between the 2 pathways determine the gonadal sex. Essentially sex determination is the enhancement of one of the 2 pathways according to genetic sex. Initially, Sry with other factors upregulates Sox9 expression in XY individuals. Afterwards the expression of Sox9 is maintained by a positive feedback loop with Fgf9 and prostaglandin D2 as well as by autoregulative ability of Sox9. If these factors reach high concentrations, then Sox9 and/or Fgf9 may inhibit the female pathway. Surprisingly, splicing, nuclear transport, and extramatrix proteins may be involved in sex determination. The male sex determination pathway switches on the expression of genes driving Sertoli cell differentiation. Sertoli cells orchestrate testicular differentiation. In the absence of Sry, the predomination of the female pathway results in the realization of a robust genetic program that drives ovarian differentiation.

2

Sex determination in 6 bovid species by duplex PCR

100%

Prashant. , Gour D. S. , Dubey P. P. , Jain A. , Gupta S. C. , Joshi B. K. , Kumar D.

Journal of Applied Genetics

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2008

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tom 49

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nr 4

379-381

EN

Sex determination in domestic animals is of potential value to livestock breeding programs. The aim of this study was to develop a simple and accurate PCR-based sex determination protocol, which can be applicable to 6 major domesticated species of the family Bovidae, viz. Bos frontalis, B. grunniens, B. indicus, Bubalus bubalis, Capra hircus, and Ovis aries. In silico analysis was done to identify conserved DNA sequence in the HMG box region of the sex-determining region of the Y-chromosome (SRY gene) across the bovids. Duplex PCR assay, including the SRY gene and the GAPDH housekeeping gene, was optimized by using genomic DNA extracted from blood samples of known sex. It was possible to identify the sex of animals by amplifying both gender-specific (SRY) and autosomal (GAPDH) genes simultaneously in the duplex reaction, with the male yielding two bands and the female one band. The protocol was subjected to a blind test that showed a 100 percent specificity and accuracy, thus it can be used in sex determination in livestock breeding programs.

3

Karyological investigations on seven weevil species (Coleoptera, Curculionidae).

88%

Lachowska D. , Holecova M.

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nr 3-4

111-114

EN

Karyological studies were carried out on seven Palaearctic weevils. The following chromosome numbers were found in individual species, i.e. Otiorhynchus niger (F.), Phyllobius viridearis (Laich.), Phyllobius scutellaris Redt., Phyllobius calcaratus (F.), Polydrusus cervinus (L.), and Brachyderes incanus (L.) 2n=22, n%=10+Xyp, in Lixus elegantulus (Boh.) 2n=22, n%=21+Xyp. The heterochromosomes of all the examined species form, in the first meiotic metaphase, a typical parachute bivalent.

4

Chromosome number in nine beetle species (Coleoptera: Bruchidae, Apionidae, Curculionidae)

75%

Lachowska D. , Holecov? M. , Ro?ek M.

Folia Biologica

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1998

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tom 46

41-46

EN

Mitotic and meiotic chromosomes were studied in nine beetle species from three families, viz. Bruchidae: Bruchus pisorum L.) (2n=34, no%=16+Xy); Apionidae: Legaricapion pisi (F.) (2n=22, n%=10+Xyp); Curculionidae: Otiorhynchus opulentus Germ., Polydrusus marginatus Steph., Polydrusus viridicinctus Gyll., Liophloeus lentus Germ., Liophloeus gibbus Boh. (2n=22, n%=10+Xyp), Larinodontes obtusus Gyll. (2n=40, n%=19+Xyp), Zacladus geranii (Payk.) (2n=28, n%=13+Xyp). In the first meiotic metaphase the heterochromosomes of eight examined species formed a typical parachute bivalent. The chromosome number and sex determining system of seven species were described for the first time.

5

Chromosome survey in seven bisexual species of weevils (Coleoptera, Curculionidae)

75%

Lachowska D.

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nr 3-4

111-113

EN

Karyological details were studied in males of seven weevil species. The following number of chromosomes were found in individual species: 2n=32, n_=15+Xyp in Gymnetron tetrum (F.) and Gymnetron smreczynski Fremuth, 2n=44, n_=21+Xyp in Cionus tuberculosus (Scop.), 2n=38, n_=18+Xyp in Cionus hortulanus (Geoffr.), Cionus ganglbaueri Wingelm. and Cionus nigritarsis Reitt., 2n=42, n_=20+Xyp in Cionus olivieri Rosensch. In the first meiotic metaphase the heterochromosomes of all the examined species formed a typical parachute bivalent. The chromosome number and sex determining system were described for the first time.

6

Karyological notes on six beetle species from Armenia (Coleoptera: Tenebrionidae, Cerambycidae, Curculionidae)

75%

Holecova M. , Lachowska D. , Karagyan G.

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tom 50

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nr 1-2

9-12

EN

Karyotypic details were studied in males of six beetle species from three families, viz. Tenebrionidae: Dailognatha pumila Bdy. (2n=20, n male= 9+Xyp), Pachyscelis musiva Menetr. (2n=18, n male= 8+Xyp), Pimelia capito Kryn. (2n = 18, n male= 8+Xyp); Cerambycidae: Agapanthia walteri Reitt. (2n=20, n male = 9+Xyp), Agapanthia korostelevi Danilevsky (2n=20, n male = 9 + Xyp); Curculionidae: Phyllobius caucasicus Stierl. (2n = 22, n male=10+Xyp). The chromosome number and sex determining system of all beetle species are described for the first time. Evolutionary trends in karyotypes of the studied beetle groups are briefly discussed.

7

Karyological notes on three weevil species from Armenia (Coleoptera, Curculionidae, Cleoninae)

63%

Holecova M. , Rozek M. , Karagyan G.

Folia Biologica

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2000

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tom 48

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nr 1-2

25-27

EN

Karyological studies were carried out on three Armenian weevil species from the subfamily Cleoninae. The following chromosome numbers were found in individual species: 2n = 38, n% = 18+Xyp in Menecleonus anxius (Gyllenhal, 1824), 2n=40, n% = 19+Xyp in Conorhynchus nigrivittis (Pallas, 1781) and 2n = 44, n% =21+Xyp in Lixus iridis Olivier, 1807. The heterochromosomes of all the examined species form, in the first meiotic metaphase, a typical parachute bivalent.