Figure 1. GSP-3/4 are sperm-specific proteins required for sperm meiosis. (A) Immunoblots of 50 μg of extracts from sperm-producing
fem-3(
q20) and oocyte-producing
fem-1(
hc17) whole worms or purified sperm indicate GSP-3/4 are detected only in sperm and sperm-producing animals. (B and C) Immunostaining of (B)
him-8(
e1489) and (C)
gsp-3(
tm1647)
gsp-4(
y418);
him-8(
e1489) male gonads with anti-GSP-3/4 antibody shows GSP-3/4 protein is absent in the double mutant. A faint level of nonspecific staining was observed evenly distributed in karyosome nuclei in
gsp-3(
tm1647)
gsp-4(
y418);
him-8(
e1489) mutants. Bar, 10 um. (D and E) Comparison of DNA staining of the proximal end of gonads from (D)
him-8(
e1489) and (E)
gsp-3(
tm1647)
gsp-4(
y418);
him-8(
e1489) males shows chromosome segregation defects caused by loss of GSP-3/4 proteins. Examples of chromatin bridges and incompletely separated chromosomes are indicated with yellow arrowheads. The white dashed square shows the region containing postmeiotic sperm. Bar, 5 μm. (F and G) Still frames from live-imaging analysis of (F)
him-8(
e1489) (File S2) and (G)
gsp-3(
tm1647)
gsp-4(
y418);
him-8(
e1489) (File S3) male spermatocytes expressing mCherry-histone (red) progressing through successive stages of meiotic divisions.