Gene family controls a snail's egg laying

Science ◽  
1982 ◽  
Vol 216 (4547) ◽  
pp. 720-721
Author(s):  
R Lewin
Keyword(s):  
1986 ◽  
Vol 371 (1) ◽  
pp. 49-57 ◽  
Author(s):  
Malladi Shyamala ◽  
John R. Nambu ◽  
Richard H. Scheller
Keyword(s):  

1985 ◽  
Vol 5 (7) ◽  
pp. 1872-1880 ◽  
Author(s):  
AC Mahon ◽  
JR Nambu ◽  
R Taussig ◽  
M Shyamala ◽  
A Roach ◽  
...  
Keyword(s):  

1986 ◽  
Vol 6 (7) ◽  
pp. 2026-2036 ◽  
Author(s):  
JR Nambu ◽  
RH Scheller
Keyword(s):  

1985 ◽  
Vol 5 (10) ◽  
pp. 2495-2501 ◽  
Author(s):  
J Spieth ◽  
T Blumenthal

While the nematode Caenorhabditis elegans is more primitive than most egg-laying organisms, it's vitellogenins, or yolk protein precursors, appear to be more complex. C. elegans oocytes accumulate two major classes of yolk proteins. The first consists of two polypeptides with an Mr of about 170,000 (yp170A and yp170B) encoded by a family of five closely related genes called vit-1 through vit-5. The second class consists of two smaller proteins with Mr values of 115,000 (yp115) and 88,000 (yp88) which are cut from a single precursor. Here we report the cloning and analysis of a single-copy gene (vit-6) that encodes this precursor. The lengths of the gene and its mRNA are about 5 X 10(3) base pairs. Like vit-1 through vit-5, vit-6 is expressed exclusively in adult hermaphrodites. Comparison of portions of the coding sequence indicates that vit-6 is distantly related to the vit-1 through vit-5 gene family. Thus, even though the two classes of yolk proteins are antigenically and physically distinct, they are encoded by a single highly diverged gene family.


1997 ◽  
Vol 2 (4) ◽  
pp. 261-271 ◽  
Author(s):  
Alexander Kurosky ◽  
Edwin L. Gorham ◽  
Walter R. A. Van Heumen ◽  
Anna T. Garcia ◽  
John S. Smith ◽  
...  

1985 ◽  
Vol 5 (10) ◽  
pp. 2495-2501
Author(s):  
J Spieth ◽  
T Blumenthal

While the nematode Caenorhabditis elegans is more primitive than most egg-laying organisms, it's vitellogenins, or yolk protein precursors, appear to be more complex. C. elegans oocytes accumulate two major classes of yolk proteins. The first consists of two polypeptides with an Mr of about 170,000 (yp170A and yp170B) encoded by a family of five closely related genes called vit-1 through vit-5. The second class consists of two smaller proteins with Mr values of 115,000 (yp115) and 88,000 (yp88) which are cut from a single precursor. Here we report the cloning and analysis of a single-copy gene (vit-6) that encodes this precursor. The lengths of the gene and its mRNA are about 5 X 10(3) base pairs. Like vit-1 through vit-5, vit-6 is expressed exclusively in adult hermaphrodites. Comparison of portions of the coding sequence indicates that vit-6 is distantly related to the vit-1 through vit-5 gene family. Thus, even though the two classes of yolk proteins are antigenically and physically distinct, they are encoded by a single highly diverged gene family.


1997 ◽  
Vol 78 (6) ◽  
pp. 2859-2869 ◽  
Author(s):  
Petra M. Hermann ◽  
Robert P. J. de Lange ◽  
Anton W. Pieneman ◽  
Andries ter Maat ◽  
Rene F. Jansen

Hermann, Petra M., Robert P. J. de Lange, Anton W. Pieneman, Andries ter Maat, and Rene F. Jansen. Role of neuropeptides encoded on CDCH-1 gene in the organization of egg-laying behavior in the pond snail, Lymnaea stagnalis. J. Neurophysiol. 78: 2859–2869, 1997. Egg laying in the pond snail Lymnaea stagnalis is triggered by a discharge of the neuroendocrine caudodorsal cells (CDCs). The CDCs expresses three different caudorsal cell hormone (CDCH) genes. This gene family expresses, in total, 11 different peptides among which is the ovulation hormone. Besides the CDCs, the CDCH gene family is expressed in other central and peripheral neurons. In this study, we investigated the roles the different CDCH peptides play in the organization of egg-laying behavior. Egg-laying behavior is a sequence of stereotyped movements in which three phases can be distinguished: resting, turning, and oviposition. We have used the excitation of right pedal N (RPeN) motor neurons as a simple analogue of shell-turning behavior, one of the elements of egg-laying behavior. RPeN motor neurons were inhibited during the resting phase of egg laying but were subsequently excited at the onset of and during the turning phase. The excitatory effect could be evoked by application of beta3-CDCP on RPeN motor neurons in the CNS as well as in isolation but not by the ovulation hormone, alpha-CDCP or Calfluxin, the other CDCH-1 peptides tested. The ovulation hormone itself caused inhibition of RPeN motor neurons. Anti-CDCH–1 positive fiber tracts were found close to the cell bodies and axons of the RPeN motor neurons. Electrical stimulation of a nerve that contains these fibers resulted in excitation of the RPeN motor neurons. The effects of injection of CDCH-1 peptides into intact animals correlated well with the effects of these peptides on RPeN motor neurons. Injection of beta3-CDCP or alpha-CDCP into intact animals resulted in immediate turning behavior in the absence of egg laying itself. The ovulation hormone and Calfluxin had no immediate effect on the behavior. Furthermore, our data indicate that the individual CDCH-1 peptides act on different targets.


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