摘要:

Teleostean fishes constitute a proliferous evolutionary grade, which shows a correspondingly diverse array of sex-mechanisms. Although most species are gonochorists, many groups have independently evolved monoecy as a response to varying degrees of breeding isolation. On the other hand, cytologically expressed heterogamety distinguishes several groups, especially those represented by the deep-sea species investigated, which belong to primitive and intermediate orders.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1970)99<131:HITF>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1970

数据来源: Taylor

摘要:

The sibling species Fundulus olivaceus and Fundulus notatus have karyotypes comprised of 48 and 40 chromosomes, respectively. The karyotype of F. notatus is probably derived from one similar to that of F. olivaceus by a Robertsonian change involving centric fusion.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1970)99<139:AAOANH>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1970

数据来源: Taylor

摘要:

The esterase enzymes of the tissues of Atlantic herring (Clupea harengus harengus) were analyzed by starch gel electrophoresis. Four sets of esterase bands were distinguished by their electrophoretic mobility, their relative activity with the two substrates, alpha-naphthyl acetate and alpha-naphthyl butyrate, and their relative concentrations in plasma, liver, and heart tissues. All of the esterases were inhibited by 10−4M solutions of dichlorvos, an organophosphate inhibitor, but none was inhibited by 10−4M eserine sulfate or by 10−4M EDTA. Polymorphism was noted in all four sets of esterases. Evidence for the genetic control of the fastest migrating set was obtained from population genetic analyses. In this set of esterases, five distinct bands occurred either singly or in pairs. The observed distribution of the three most common bands fits the hypothesis that they are controlled by a set of autosomal alleles. The two rarest bands occurred only in the heterozygous state, as would be expected. Differences in frequencies of two of the genes were detected between herring taken in Western Maine waters and on Georges Bank.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1970)99<147:PITEOA>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1970

数据来源: Taylor

摘要:

Genetic studies of tuna began with immunological techniques on blood groups and were followed by immunoelectrophoresis and electrophoresis with improved histochemical staining techniques. These increased our ability to study polymorphisms in soluble proteins and enzymes not only in blood but also in tissues or organs in tuna.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1970)99<152:IABGOT>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1970

数据来源: Taylor

摘要:

Seven hatchery populations and seven of eight wild populations of brook trout sampled were polymorphic for both the LDH-B and the transferrin loci. The degree of variations of allele frequencies as well as of the amount of heterozygosity was generally greater among hatchery fish than those from natural populations. Calculations of interpopulation heterogeneities of allele frequency differences permitted distinguishing all of the hatchery strains, but not all of the small wild populations, from each other. While gross intra-population heterogeneity was found, an assessment of the breeding structure of wild brook trout in a stream was not possible.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1970)99<179:PFLATL>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1970

数据来源: Taylor

摘要:

Two of the five lactate dehydrogenase (LDH) subunit loci known to exist in salmonid fishes were obtained in heterozygous condition in the hybrid of lake trout (Salvelinus namaycush Walbaum) X brook trout (S. fontinalis Mitchill) and linkage tests were performed. These loci (and subunits), designated A and B, are both regarded as being duplicates of and therefore homologous to the B locus of higher vertebrates. In first backcrosses of doubly heterozygous males to homozygous brook trout females there was a significant deficiency of parental combinations among the offspring. However, when the doubly heterozygous parents were female, there were equal numbers of the four backcross progeny types produced, indicating independent assortment. Second backcrosses to brook trout homozygotes produced similar results. Among first backcross families there was a range of values of parental combinations of from 13.5–30.0%, while among second backcrosses this value ranged from 1.0–66.0%. The latter value is an exceptional case in which parental combinations were in excess. The data thus do not indicate linkage of the A and B genes. Possible causes of the disturbed joint segregation in males are discussed.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1970)99<193:NSOTLD>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1970

数据来源: Taylor

摘要:

Three brook trout transferrins, designated A, B and C, were purified by use of rivanol precipitation and gradient elution chromatography with DEAE-Cellulose. Physical and chemical analyses of the purified transferrins demonstrated that each type had at least four sialic acids attached to the protein moiety and that the A type of transferrin has a number of amino acid substitutions, as shown by amino acid analysis and fingerprinting. No differences could be shown between the B and C types. Analyses of molecular weights were inconclusive.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1970)99<207:SPPOTI>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1970

数据来源: Taylor

摘要:

Functional and evolutionary dynamics of polymorphic esterases in catostomid fishes are discussed using Catostomus clarki from the Colorado River to develop a consideration of patterns of variation. Since esterase phenotypes among other closely related species provide support for some of the hypotheses formulated from investigations of C. clarki, brief mention is made of C. santaanae, C. platyrhynchus, C. discobolus, C. columbianus, C. plebeius, and C. insignis.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1970)99<219:FAEDOP>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1970

数据来源: Taylor

摘要:

The first fertile hybrid generation ever known to have been produced artificially between salmon (Salmo salar L.) and trout (Salmo trutta L.) has been examined electrophoretically. To find out the mode of inheritance for the protein systems investigated the F1hybrids were compared with samples of salmon and trout of the parental populations as well as a sample of F2hybrids. All fishes were 2+ years of age. In the protein systems where protein or enzyme activity was detected 17 were more or less complete summations of the parental patterns in the F1hybrid thereby displaying a codominant relationship between the parental genes. Four protein systems were identical in both species. Dominance of trout genes was the most striking feature of the F2hybrids, since the action of all salmon genes was suppressed. In four patterns one or more zones had been added to the theoretical maximum pattern obtained by simply mixing the parental patterns. This phenomenon was attributed to the action of multiple gene systems displaying transgressive segregation.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1970)99<229:EAOHBS>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1970

数据来源: Taylor

摘要:

The classification and study of evolutionary relationships of salmonid fishes have produced a large amount of classical systematic literature; however, many problems remain unresolved.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1970)99<237:TAOCAB>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1970

数据来源: Taylor