Worm Breeder's Gazette 9(1): 68

These abstracts should not be cited in bibliographies. Material contained herein should be treated as personal communication and should be cited as such only with the consent of the author.

Nuclear aberrations and loss of synaptonemal complexes in response to Diethylstilbestrol in Caenorhabditis elegans hermaphrodites

P. Goldstein

In Caenorhabditis viability and fertility 
is observed after treatment with DES.  The decrease in life span is 
associated with senescent morphology of meiotic prophase nuclei, such 
that nuclei from young and old specimens cannot be differentiated.  
Aging in oocytes at the pachytene stage of meiotic prophase is 
manifested by nucleo-cytoplasmic aberrations, increased density of the 
nucleoplasm and cytoplasm and decrease in numbers of mitochondria.  
Increasing concentrations of DES are characterized by concomittant 
decrease in fertility and increased production of abnormal gametes.  
At DES concentrations higher than 1.25  g/ml, synaptonemal complexes(
SC) are absent from the nuclei, thus, effective pairing and 
segregation of homologous chromosomes is not possible.  The absence of 
SCs may be the result of: 1) a premeiotic colchicine effect that 
influences pairing of chromosomes; 2) changes in the structure of the 
DNA due to DES binding that results in changes in expression of the 
DNA; and 3) changes in temporal DNA synthesis in response to DES.  
Since the SC is essential for regulating pairing and subsequent 
separation of bivalents, the lack of an SC explains the loss of 
fertility, due to the production of unbalanced gametes, observed in 
DES treated specimens.