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F Gasser

Publications and source records attributed to F Gasser.

At least 73 records · Page 4Linked to original sources
PubMed1984

Maternal effect and embryonic gene expression for lactate dehydrogenase B (LDH-B), glucose-6-phosphate dehydrogenase (G6PDH), and peptidase (PEP-1) during the development of Pleurodeles waltl (urodele amphibian).

The polymorphism of three enzymes [lactate dehydrogenase B (LDH-B), glucose-6-phosphate dehydrogenase, (G6PDH), and peptidase-1 (PEP-1)] in Pleurodeles waltl has allowed the expression of the corresponding loci to be followed during the development of spawnings arising from various crosses. A maternal effect lasting up to the late tail-bud stage (approx. stage 28) was shown for PEP-1. A similar situation was observed for LDH-B and G6PDH. The embryonic alleles present retarded expression: from about stage 28 for PEP-1 and G6PDH and from about stages 22 to 24 (the young tail-bud stage) for LDH-B.

Animals↗
PubMed1983

A genetic study of various enzyme polymorphisms in Pleurodeles waltlii (Urodele amphibian). I. Lactate dehydrogenase-B and glucose-6-phosphate dehydrogenase.

On starch gel electrophoresis of erythrocyte hemolysates of Pleurodeles waltlii (Urodele Amphibian), both lactate dehydrogenase-B (LDH-B) and glucose-6-phosphate dehydrogenase (G6PDH) show polymorphism that depends on a pair of autosomal codominant alleles, confirmed by analysis of gynogenesis progeny. Diploid gynogenesis results from fusion of the female pronucleus with the second polar body. The heterozygous state of a female for a given character is maintained in certain progeny when crossing-over occurs between the locus in question and the centromere. So the high proportion of heterozygotes (45.7% for LDH-B and 76% for G6PDH) indicates the high frequency of crossing-over and hence the large distance between each of the loci and the centromere.

Animals↗
PubMed1983

A genetic study of various enzyme polymorphisms in Pleurodeles waltlii (Urodele Amphibian). II. Peptidases: demonstration of sex linkage.

The existence of four peptidases was demonstrated by starch gel electrophoresis in Pleurodeles waltlii: PEP-1, PEP-2, PEP-3, and PEP-4. Peptidases-3 and -4 are monomorphic, and peptidases-1 and -2 are polymorphic. The heredity of the polymorphisms was studied using individuals arising from crosses or of gynogenetic origin. Peptidase-1 is dimeric; its polymorphism depends on a pair of codominant alleles, Pep-1A and Pep-1B, which are situated on the Z and W sex chromosomes, respectively, in close proximity to, or even within, the sex differential segment. As the differential segment is very close to the centromere, the PEP-1 locus therefore also appears to be closely linked to it. Expression of the PEP-1 locus was shown to be independent of the sex hormone environment. This locus is the first case reported in amphibians of an enzyme marker linked to the genetic sex. It allows the sex of PLeurodeles to be determined before they reach sexual maturity. Peptidase-2 is monomeric. Its polymorphism depends on a pair of codominant alleles on an autosomal PEP-2 locus. The high proportion of heterozygous animals in the gynogenetic offspring of females heterozygous for the PEP-2 locus indicates segregation which is independent of the centromere. Analysis of the offspring of doubly heterozygous females (i.e., for two of the loci--LDH-B, G6PDH, PEP-1, and PEP-2) shows that the four loci are independent.

Animals↗
PubMed1983

A genetic study of various enzyme polymorphisms in Pleurodeles waltlii (Urodele, Amphibian). III. The relationship between sex-linked peptidase-1 expression and gene-dose effects.

Erythrocyte peptidase-1 was analyzed by electrophoresis in various types of triploid Pleurodeles waltlii. Densitometric analysis of the zymograms showed (1) the existence of a gene-dose effect and (2) the presence of two Pep-1B alleles for one Pep-1A allele in heterozygous triploid females of biparental origin. Owing to the sex linkage of the PEP-1 locus (alleles Pep-1A and Pep-1B situated on the Z and W sex chromosomes, respectively), the results show that the sex genotype of these females is ZWW. In a particular line called series 103, the existence of a null allele was demonstrated. Densitometric analysis of females which were Pep-1A/Pep-10 (ZW), Pep-10/Pep-10 (WW), and Pep-1A/Pep-10/Pep-10 (ZWW) confirmed the gene-dose effect.

Animals↗
PubMed1975

[Impression methods].

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Dental Impression Technique↗