Section 10 — Developmental Genetics 



viously in the phaen analysis of some quantitative 

 characters by Brody and others. This method, 

 naturally with its limitations, still has many 

 really useful aspects and so the authors, analys- 

 ing during some years different species, races, 

 hybrid forms, back cross generations, are in- 

 clined to think that this effort had given some 

 results in the "kinetic" point of view of the 

 epigenesis of quantitative characters. 



In any case one must take into consideration 

 that the so-called "allometrical ground plan" 

 in Needham's sense shows little if any change in 

 respect of the different quantitative varieties. 

 This fact precludes not the possibility of the 

 different manifestation of the adult quantitative 

 characters. In realizing the final state the quan- 

 titative characters are developing in many ways: 

 different startpoints, different velocity of growth 

 in the subsequent development phases, accelera- 

 tions and compensations. It is not difficult to 

 perceive sometimes the "transit-heterosis" state. 

 This has practical importance. 



The differences of reciprocal hybrids during the 

 postembryonal development are also the results 

 of kinetic changes and describing them in this 

 sense is much more accessible than in the end state. 



From the linear transformations of the growth 

 curves one can conclude about the degree of the 

 homoestasis by means of the deviations from 

 linear regressions for each separate genotype 

 and the so-called intraspecific allometry is 



available in the phaen-analysis of quantitative 

 characters. 



10.40. Contribution to the Teratogenic Effect of 

 Thalidomide in Golden Hamsters and Mice. 



H. Stengel, K. H. Degenhardt, and G. 

 Badtke. (Frankfurt/Main, Germany). 



Gross analysis of a control group of 124 

 newly-born golden hamsters has not shown any 

 malformations. However, after processing the 

 new-born animals for skeletal study (alizarin, 

 glycerin) the examination disclosed several 

 malformations: 1 x a slight reduction of the 

 maxilla, 2 / a bent radius and ulna on both 

 sides (right > left), and 19 < defects of the 

 centra of the vertebrae, especially in the cervical 

 region. For the treatment, thalidomide was 

 suspended in 1 per cent carboxymethylcellulose. 

 Daily doses of 10 mg or 100 mg thalidomide/ 

 lOOg body weight were administered female 

 golden hamsters by oral intubation for a period 

 of eight months. Gross analysis of 1 19 offspring 

 in the 10 mg series showed no malformations. 

 The skeletal system, however, revealed various 

 malformations: 2x a slight reduction of the 



maxilla and 15 x defects of the centra of the 

 vertebrae, especially in the cervical region. Fur- 

 thermore, in more than 50 per cent of the ani- 

 mals microphthalmia of various degrees occur- 

 red, and in some cases other eye abnormalities. 

 Of the group treated with 100 mg none of 127 

 new-borns was found to have external malfor- 

 mations. Again a number of skeletal malforma- 

 tions were found: 1 X a reduction of the 

 mandibula, 30 x defects of the centra of the 

 vertrebrae, and 4 x chondrodysplastic changes 

 in the long bones of the upper limbs (right > 

 left). The eyes are being examined histologically. 

 Analogous experiments have also been done 

 with mice of the inbred strain C57 BL/6 Han- 

 nover. In the control group of 149, 16 abnormal- 

 ities of the vertebrae have been found. Two ani- 

 mals had an extreme microphthalmia. Following 

 treatment with 10 mg, 117 new-borns could be 

 analysed. 21 showed abnormalities of the verte- 

 bral column, 5 defects of the jaws, 2 cleft palate, 

 3 extreme microphthalmia and 1 a kidney dys- 

 plasia on the right. Of the 118 animals from 

 25 litters treated with 100 mg thalidomide 

 100 g b.w. 109 skeletal systems have been analy- 

 sed, 10 x abnormalities of the vertebral column 

 occurred, 5 defects of the jaws, 7 x micro- 

 phthalmia, 2 x cleft palate and 1 x aplasia of 

 the abdominal organs. Histological investigations 

 are being carried out. 



10.41. An Experimental Contribution to the Determi- 

 nation of Origins of Complex Abnormalities of 

 the Anterior Chamber of the Eye. K. H. Degen- 

 hardt and G. Badtke. (Frankfurt a/M, 

 Germany). 



Complex abnormalities of the anterior part of 

 the eye known in human beings as "Peter's 

 malformation of the cornea, congenital leucoma 

 and staphyloma of the cornea", differ chiefly in 

 the various strengths of the single symptoms. 

 Features in common are opacity of the cornea 

 and adhesion between the opaque area of the 

 cornea and the iris or the persistent pupillary 

 membrane. Changes in the structure of the lens 

 consist of different degrees of cataract, leading 

 up to aphakia. Microphthalmia and coloboma 

 are also observed. The pathogenesis remains as 

 yet unclear. Peters thought that disturbance due 

 to the separation of the lens from the ectoderm 

 was the cause; but up to now it has not been 

 possible to prove this using embryological mater- 

 ials. The alternative theory that the cause is dis- 

 turbance by the development of the mesenchyma 

 has also not yet been proved. 



Distinct disturbances due to the separation of 



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