Christina M. Richards

Inheritance of Enzymes and Blood Proteins in the Leopard Frog, Rana pipiens: Three Linkage Groups Established

Individuals from natural populations of the leopard frog, Rana pipiens, were analyzed for electrophoretic differences in blood proteins and enzymes from an amputated digit. The proteins examined represent products of 72 loci. Presumptive heterozygotes at multiple loci were selected for experimental crosses. Mendelian inheritance of 18 protein variations were demonstrated in the offspring. Tests for linkage or independent assortment were performed for 75 locus pairs. Three linkage groups were established. Linkage group 1 contains two loci, aconitase-1 (Acon1) and serum albumin (Alb), with a 19% recombination frequency between them. Linkage group 2 contains four loci, glyoxalase (Gly), acid phosphatase-1 (Ap1), acid phosphatase-2 (AP2), and esterase-5 (Est5). The data show the relationships Gly-21.1%-AP1-0%-AP2-6.3%-Est5, and Gly-25.6%-Est5. Linkage group 3 consists of four closely linked esterase loci. The data, Est1-5.1%-Est6, Est6-1.8%-Est10-1.9%-Est4 and Est6-3.0%-Est4, do not establish a complete order but suggest that Est10 is between Est4 and Est6. These results, with data demonstrating apparent independent assortment of 67 other locus pairs, provide a foundation for establishing the frog genetic map.

Development of Biologically Defined Strains of Amphibians

Throughout this Symposium (1) two threads of thought are implicit. The iirst is that the amphibian is a desirable organism on which to conduct tumor and virus research, but that living amphibian material, either in culture or as the whole animal, must be brought under more adequate biological control. Reference has repeatedly been made to the use of wild amphibians in a variety of experimental situations. In no case has reference been made to the nutritional or health status of the animals involved. The only attempts at genetic definition have been by reference to karyotyping, with the exception of work with some urodeles which have been maintained in laboratory colonies for significant periods. It is evident from the work of Moore (2) and McKinnell (3) that the biology of Rana pipiens from closely adjacent populations may differ markedly. Important genetic differences among animals from different commercial shipments must be expected. The second line of thought is that viruses are somehow associated with the development of the Lucke renal adenocarcinoma. Only the approach developed by Tweedell (4) and utilized by Mulcare (5) has routinely resulted in the induction of tumors by inoculation of a virus-containing fraction. Tumors have been induced in other cases (6) but the incidence has been below that desirable for routine analysis of the biology of this tumor. Granoff (7) has specifically indicated the failure to induce tumors in frogs with cultured agents isolated from tumor-bearing frogs.

The Development of Color Dimorphism in Hyperolius v. viridiflavus, A Reed Frog from Kenya

and ducklings for objects of different colors. Psych. Reports 2:477-483. HIGHTON, R. 1962. Revision of North American salamanders of the genus Plethodon. Bull. Florida State Mus. 6:335-367. . 1971. Distributional interactions among eastern North American salamanders of the genus Plethodon. VPI and State Univ. Res. Div. Monog. 4:139-188. HOWARD, R. R., AND E. D. BRODIE, JR. 1973. A Batesian mimetic complex in salamanders: Responses of avian predators. Herpetologica 29:3341.

Sources of Amphibians for Research

The program of the Amphibian Facility of The University of Michigan has been described in the reports listed in the bibliography. Nace (1968) contains an overall description; the other papers cited describe specific features. Nace (1970) reproduces the information forms which record data on demography, genetics, and pathology of the animals in the Amphibian Facility. It also includes tabular information on the

A scanning electron microscopic study of differentiation of the digital pad in regenerating digits of the kenyan reed frog, Hyperolius viridiflavus ferniquei†‡

Newly metamorphosed Kenyan reed frogs, Hyperolius viridiflavus ferniquei, are able to regenerate amputated digits. The terminal digital pad is also completely reformed. Differentiation of the regenerating digital pad was studied by scanning electron microscopy. External differentiation of the digital pad began late in the second postamputational week with the appearance of small patches of specialized epidermal cells on the ventral surface of the regenerating digit. The differentiation of the pad spread out radially until late in the fourth week, when its overall shape approximated that of the normal digital pad. The appearance of patches of digital pad epidermis on the ends of spike regenerates arising from the forearm was also confirmed.

A New Species of Reed Frog, Hyperolius cystocandicans, from Montane Kenya

A new species of montane Hyperolius, H. cystocandicans, the silverbladdered reed frog, is described from Tigoni, Kenya. Although it is sympatric with and morphologically similar to H. montanus, it is readily distinguished by the presence of a silvery-white opaque bladder visible through the semi-transparent ventral skin and by the presence of pectoral, brachial and digital glands in males; these glands are absent in H. montanus. Hybrids between the two do not develop. Collections from Meru and Maua are tentatively assigned to H. cystocandicans.

A NEW COLOR PATTERN VARIANT AND ITS INHERITANCE IN SOME MEMBERS OF THE SUPERSPECIES HYPEROLIUS VIRIDIFLAVUS (DUMÉRIL & BIBRON) (AMPHIBIA ANURA): PUBBLICAZIONI DEL CENTRO DI STUDIO PER LA FAUNISTICA ED ECOLOGIA TROPICALI DEL C.N.R.: CCXIX

SUMMARY A third color pattern variant, striped, is reported for H. v. ferniquei Mocquard, H. v. pantherinus (Steindachner) and H. v. ommatostictus Laurent (Amphibia Anura). These frogs can have the hourglass or striped pattern as juveniles. Adult females have a color pattern characteristic of the subspecies while adult males may be striped, hourglass or have the female color pattern. The striped pattern was rare in populations of H. v. ferniquei but was quite common in even small collections of H. v. pantherinus and H. v. ommatostictus. The striped gene appears to be allelic to hourglass and dominant to it. Heterozygotes for striped crossed with an hourglass mate segregate striped and hourglass in a 1:1 ratio in the progeny. The segregation continues in appropriate F2 crosses. These new data add to the complexity of an already complex polymorphic group and will ultimately contribute to a better understanding of the polymorphisms and their genetic bases.