REVUE SUISSE DE ZOOLOGIE 

 Tome 78, fasc. 4, n° 41 : 761-776 — Décembre 1971 



761 



Distribution of Lactate Dehydrogenase 

 (and its E-isozymes) in the developing 

 and adult Retina of the Guppy 



(Lebistes reticulatus) 1 



The enzyme Lactate Dehydrogenase (LDH) occurs in mammalian tissues in 

 five distinct isozymes. They can be separated by electrophoresis and stained with 

 histochemical methods, and appear as blue bands due to the réduction of a 

 tetrazolium sait to formazan. The relative intensity of the différent bands thus 

 obtained, differs considerably from tissue to tissue. In the heart the most anodic 

 bands predominate, whereas in the skeletal muscle the most cathodic bands are 

 more pronounced. It has been shown that in mammals each of the five isozymes 

 is a tetramer composed of two subunits, called A and B, encoded by two différent 

 gènes. In addition, a third subunit, C, is présent in the testis of several mammals 

 and birds. (Batellino et ai, 1968). 



The LDH isozyme patterns of fish show great variation. From one to 

 18 différent isozymes have been found in some thirty species tested (Markert and 

 Faulhaber, 1965; Massaro and Markert, 1968). One set of isozymes, with 

 extrême anodal electrophoretic mobility, has been observed in the eye and brain 

 only of many teleosts (E-isozymes) (fîg. 1). It has been suggested by various 

 authors, that thèse E-isozymes réside in the retina, but apart from the work of 

 Whitt and Booth (1970) the teleostean retina has not been subjected to histo- 



1 Manuscript received for publication, 28 March 1971. 



by 



Yvette KUNZ 



Department of Zoology, University Collège Dublin (Ireland) 



with 19 figures 



Rev. Suisse de Zool., T. 78, 1971. 



49 



