Knockout of the folate transporter folt-1 causes germline and somatic defects in C. elegans.
BACKGROUND
The C. elegans gene folt-1 is an ortholog of the human reduced folate carrier gene. The FOLT-1 protein has been shown to transport folate and to be involved in uptake of exogenous folate by worms. A knockout mutation of the gene, folt-1(ok1460), was shown to cause sterility, and here we investigate the source of the sterility and the effect of the folt-1 knockout on somatic function.


RESULTS
Our results show that folt-1(ok1460) knockout hermaphrodites have a substantially reduced germline, generate a small number of functional sperm, and only rarely produce a functional oocyte. We found no evidence of increased apoptosis in the germline of folt-1 knockout mutants, suggesting that germline proliferation is defective. While folt-1 knockout males are fertile, their rate of spermatogenesis was severely diminished, and the males were very poor maters. The mating defect is likely due to compromised metabolism and/or other somatic functions, as folt-1 knockout hermaphrodites displayed a shortened lifespan and elongated defecation intervals.


CONCLUSIONS
The FOLT-1 protein function affects both the soma and the germline. folt-1(ok1460) hermaphrodites suffer severely diminished lifespan and germline defects that result in sterility. Germline defects associated with folate deficiency appear widespread in animals, being found in humans, mice, fruit flies, and here, nematodes.
Austin
Misa U
MU
Department of Biological Sciences, California State University Pomona, CA 91768, USA.
Liau
Wei-Siang
WS
Balamurugan
Krishnaswamy
K
Ashokkumar
Balasubramaniem
B
Said
Hamid M
HM
LaMunyon
Craig W
CW
D000818:Animals; D017173:Caenorhabditis elegans / Q000235:genetics / Q000378:metabolism*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism*; D012734:Disorders of Sex Development; D005492:Folic Acid / Q000378:metabolism; D055786:Gene Knockout Techniques; D005854:Germ Cells / Q000378:metabolism; D008136:Longevity; D008297:Male; D027361:Organic Anion Transporters / Q000235:genetics / Q000378:metabolism*
D029742:Caenorhabditis elegans Proteins; C550335:Folt-1 protein, C elegans; D027361:Organic Anion Transporters; D005492:Folic Acid