W A T E R   F R O G     N E W S L E T T E R

        	December  1997


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**What's Happening in Water frog Research**

We're starting a column for the water frog newsletter in which
various laboratories and research groups take turns describing
their current research on water frogs. This will help members of
the water frog community get to know each other better. It may
help us find ways of cooperating and collaborating with each
other, but it will also let us know what exciting things are
happening in water frog research. Let us know if you'd like 
to describe your program soon.

Our first contribution comes from the Institute of Zoology of the
Ukrainian National Academy of Science in Kiev, Ukraine. 

            Current research on water frogs
Sergei Mezhzherin, Institute of Zoology of the
Ukrainian National Academy of Science in Kiev, Ukraine

At the Institute of Zoology, we are investigating hybrid
populations of water frogs from within Kiev and from neighboring
regions. The main aim of this investigation is to describe the
pattern, in space and time, of introgression of an Ldh-B allele
characteristic of Rana lessonae into Rana ridibunda. One of the
most interesting results so far is that introgressive alleles
accumulate in Rana ridibunda populations of urbanized localities.
The usual frequency of the introgressive allele is about 5-10%,
but in some populations within Kiev, the frequency reaches about

This year, we compared the frequencies of the introgressive Ldh-B
allele in freshly metamorphosed  marsh frogs collected in the
summer of 1997 with the frequencies in freshly metamorphosed marsh
frogs collected at the same localities in 1991. This comparison
demonstrates frequency stability of the introgressive allele for
the last six years. This observation is rather interesting, given
the neutralistic-adaptationistic discussion, because the
introgressed allele has an aberrant phenotype and presumably is
not coadapted with genome of Rana ridibunda. The observation of
nuclear gene introgression is similar to observations of Rana
lessonae mtDNA introgression into Rana ridibunda in many central
European populations. It would be very interesting to integrate
these investigations by comparing both Ldh-B alleles and mtDNA
phenotypes in marsh frogs with different genomes; investigation
of the chromosomes of these frogs would also be interesting.

The general directions of our current investigation is
integration of morphometric and genetical data, and specifically,
to define the influence, at the phenotypic level, of allelic
introgression at single loci. It would also be very interesting
to study the relationships between developmental stability of
characters and allelic introgression.

A future direction of our water frog investigation is the
analysis of the genetic structure of these species and the 
specificity of hybridization processes as influenced by the
radioactive pollution released at Chernobyl.  

Our recent investigations are reflected in the following

Mezhzherin, S. V., and S. Y. Morozov-Leonov. 1996. Genetical
analysis of hybrid population structure of green frog complex
Rana esculenta L. (Amphibia, Ranidae) from Vohlin'. Tsitologia i
Genetika 30(1): 48-53 (in Russian with English translation).

Pisanetz, E. M., S. V. Mezhzherin, and N. N. Scherbak. 1996.
Hybridization and external morphology studying of Asian toads
(Amphibia: Bufonidae) with description of a new species Bufo
shaartusiensis sp. nova. Dopovidy of National Academy of Science
of Ukraine 5:147-151 (in Russian).

Mezhzherin, S.V., S. Y. Morozov-Leonov, and E. A. Piontkovskaya.
1997. Allozyme variability of endemic species of amphibians in
the eastern Carpathians. Biological Diversity of Carpathian
Reserve, Kiev 352-367 (in Ukrainian).

Mezhzherin, S. V., and S. Y. Morozov-Leonov. 1997. Gene
introgression in hybrid populations of green frogs of Rana
esculenta L., 1758 complex (Amphibia, Ranidae) from the Dnieper
Basin. Russ. J. Genet. 33(1): 358-364 (English translation).

Mezhzherin, S. V. 1997. Mutation units of loci coding of lactate
dehydrogenase and their directed changes on the phylogenesis of
vertebrates. Biol. Bull. (1): 27-34 (English translation).

Mezhzherin, S. V. 1997. Genetic differentiation and species
identity of the marsh frog, Rana ridibunda Pall. (Amphibia,
Ranidae) from Eastern Kazakhstan. Zoological zhurnal 76(8):
933-939 (English translation).

Mezhzherin, S. V., and S. Y. Morozov-Leonov. 1998. Allozyme
variation and genetic relationships of hylid frog Hyla arborea
(Amphibia, Hylidae) of the Mountainous Crimea. Tsitologia i
genetika (in press).

Mezhzherin, S. V., S. Y. Morozov-Leonov, T. I. Kotenko, and E. A.
Piontkovskaya. 1998. Biochemical genetic differentiation of the
newts (Amphibia, Salamandridae, Triturus). Dopovidi NAN Ukrainy 
(in press).

Mezhzherin, S. V. 1998. Allozyme variation character of the
lactate dehydrogenase (E.C. in vertebrate animals.
Russ. J. Genet. (in press)

Perspective directions of our investigations are biochemical
systematics and genogeography of anuran amphibians, with emphasis
on the Rana esculenta and Bufo viridis complexes. We are
especially interested in Asian taxa.  We plan further 
investigations of hybrid water frog populations, and seek 
cooperation with DNA and cytological methods. We are also
interested in comparative evolutionary genetic of allozyme
variation and genetic differentiation of amphibians in
comparisons with other classes of vertebrates.  In addition to
our work on water frogs, we continue working with all Ukrainian
species of amphibians.

I must emphasize the dangerous situation in fundamental sciences
in Ukraine. To my mind, the situation is worse than in any other
well-developed post-Soviet Union country. I haven't received my
real wages for four months. Moreover, the  Institute has no
postal service except for e-mail and therefore I can not
distribute my reprints of our publications. Reagents for
molecular genetics research and support for travel are especially
difficult to obtain.

Sergei Mezhzherin

email: root@iz.freenet.kiev.ua
tel:   (380-44) 225-1070
fax:   (380-44) 224-1569 

		       News and Views
The information here, including links to other relevant
sections, can be found at

New literature with abstracts 
Plotner, J. (in press). Genetic diversity in mitochondrial 
12S rDNA of western palearctic  water frogs (Anura, Ranidae) 
and implications for systematics. Journal of Zoological
Systematics and Evolutionary Research.

Abstract -- The nucleotide sequence of a part of the 
mitochondrial 12S rRNA gene of  eight western palearctic 
water frog species was analyzed. The results support the 
species status of Rana bedriagae, R. bergeri, R. epeirotica, 
R. lessonae, R. perezi, R. ridibunda,  R. saharica, and  
R. shqiperica. Furthermore, the  differences between the 
mt 12S rDNA segments of lake frogs from Greece and Yugoslavia 
on the one hand and the 12S rDNA segments of lake frogs from 
Georgia, Uzbekistan, and Turkmenistan on the other hand provide 
new evidence for the existence of two cryptic species. It seems 
very probable  that lake frogs from Georgia, Uzbekistan, and 
Turkmenistan belong to R. ridibunda whereas lake frogs from 
Greece and Yugoslavia represent R. kurtmuelleri, a form which 
had  already been described by Gayda (1940). Additional 
investigations are needed to clarify  this problem. The very 
high similarity between the analyzed 12S rDNA segments of German
 R. ridibunda and R. lessonae support the hypothesis that  mtDNA 
of R. lessonae was transmitted into the mitochondrial gene pool 
of R. ridibunda probably as a result of backcrosses with the 
hybridogenetic hybrid R. kl. esculenta. The obtained genetic 
data confirm the very close phylogenetic relations between 
R. perezi and R. saharica. However, it is not yet clear 
whether both species represent an adelphotaxon. Furthermore, 
R. shqiperica, R. lessonae, and R. bergeri  on the one hand 
and R. ridibunda and R. bedriagae on the other hand are 
considered to be seperate lineages which seem to be 
sister taxa. 
According to the mt 12S rDNA data R. epeirotica seems to 
be closer related to the supraspecific taxon 
R. ridibunda/R. bedriagae than to 
R. lessonae/R. bergeri/R. shqiperica. Thus, it can be excluded 
that R. shqiperica and R. epeirotica represent sister species.

Key words:Ranidae, Rana, western palearctic water frogs, systematics, 
mitochondrial 12S rDNA, sequence analysis

Schmidt, B. R., Hotz, H., Anholt, B. R., Guex, G.-D. and Semlitsch, 
R. D. (in press). Factors contributing to the maintenance of the genetic 
polymorphism at the locus LDH-B in the pool frog, Rana lessonae. 
Canadian Journal of Zoology.   

Abstract -- We tested for environmental factors that may lead to
balancing  selection and to the maintenance of a genetic polymorphism at
the enzyme locus lactate dehydrogenase B (LDH-B) in the pool frog,  Rana
 lessonae.  We raised tadpoles individually in a factorial experiment 
where we manipulated temperature, food level, and food quality.  The 
only statistically significant difference among LDH-B genotypes was  for
growth rate with the heterozygote performing best.  Although the 
difference was not significant, heterozygotes also tended to perform 
best for size at metamorphosis.  However, heterozygotes did not perform
best for other traits (age at metamorphosis, survival and rate of
metamorphosis) where differences among LDH-B genotypes were not 
significant as well.  The size of the effect of LDH-B genotype  depended
on the environment, suggesting that the locus may be 
selectively neutral in some environments.  There were no 
genotype-environment interactions in the sense that reaction norms 
along environmental gradients did not cross.  When we raised tadpoles 
in groups, e/e homozygotes had a significantly higher mass and 
developed at the significantly highest rate.  In addition, there may 
be a trade off between larval and adult performance:  adult frogs show 
a different ranking in performance of LDH-B genotypes than tadpoles do. 

These results suggest that the genetic polymorphism is maintained 
through heterozygote advantage, possibly in conjunction with
antagonistic pleiotropy. 

Older abstracts newly added 
Buckley, D., B. Arano, P. Herrero, and G. Llorente. 1996. Population
structure of Moroccan water frogs:  genetic cohesion despite a 
fragmented distribution.  Journal of Zoological
Systematics and Evolutionary Research 34:173-179.

Kovacs, T. and J. Torok. 1995.   Dietary responses by Edible Frog 
(Rana esculenta complex)   to wetland habitat change in Hungary.  
Proceedings of Workshop 2 of the International Conference  on Wetlands
and Development,   Kuala Lumpur, Malaysia, 9-13 October 1995, 79-86.

Schmidt, B. R. 1996. Sexual and asexual reproduction in vertebrates. 
Trends in Ecology and Evolution 11: 253-254. 

Waterfrog bibliography
This has been updated to add publications noted between September and now.
If you have new literature citations send them to 
Hansjurg Hotz (hotz@zoolmus.unizh.ch); if you have new abstracts
send them either to frog@genetics.washington.edu or

Other Changes 
- update of the index, corrections of misspelling of names.

More extensive literature coverage
We haven't heard any opinion on this and haven't seen any contribution
 towards a more complete coverage.

A water frog session or workshop at the SEH conference in
Chambery, France, August 27-29 1998.
Nobody is intending to go to this meeting? Or do you have
absolutely no idea about what you want to present?
We print the following again as a reminder:

As was discussed at the 3rd World Congress of Herpetology
in Prague, having a water frog session of workshop at the
upcoming conference would be useful, but we still have
received no suggestions or ideas.

If you have ideas or thoughts about organizing a special
water frog program at the SEH meetings, send them to Dirk

Peter Beerli (beerli@scs.fsu.edu)