WormMine: ExpressionPattern Expr11975

• Pattern: Expression of INX-8, -9, -14, -21 and -22 overlapped closely throughout the gonad in wild-type adult hermaphrodites. In distal arms clusters of fine puncta were associated with each germ cell, as previously reported for INX-14 and INX-22 expression (Govindan et al. 2009). INX-14, -21 and -22 colocalized to puncta associated with long processes that extended from the DTC proximally, especially those running between germ cells and intercalating among them. At the distal limit of sheath cell coverage of germ cells, longer formations sometimes appeared associated with the apparent edge of the sheath cells. At the loop region of the gonad arm, individual puncta appeared in larger, higher-density aggregates. In the proximal arm puncta size was more variable, with many appearing to be considerably larger than the fine puncta seen in the distal arm. Although all innexins appeared to colocalize, INX-21 differed from the other innexins in that its expression level was relatively higher in the distal gonad compared to the proximal gonad. In contrast, the expression levels of INX-8, INX-9, INX-14, INX-22 appeared higher in the proximal gonad. Male gonads were examined and found to express INX-8, -9, -14, -21 and -22 as well. Presumptive gap junctions forming between both male distal tip cells and germ cells were detected with antibodies specific to INX-8/9, INX-14, INX-21, and INX-22. All 5 innexins are also expressed in the regions occupied by differentiated spermatocytes and sperm, with evidence of puncta formation. Examination of earlier developmental stages showed that all five innexins are expressed in the primordial gonad, consisting of somatic gonadal precursors Z1 and Z4 and the primordial germ cells Z2 and Z3. In a few serendipitous cases expression of INX-22 was detected prior to hatching, in pretzel-stage embryos. Early larval expression patterns differ from adults in that distinct, well-defined puncta potentially corresponding to gap junctions are less clearly discernible. In L2-L4 larval stages, germ cell innexins appear to be continually expressed, and somatic innexins are expressed predominantly in the DTC. In late L2 and early L3 stages, as the gonad arm lengthens, the migrating DTC seems to trail a process behind it that maintains contact with the germ cell compartment. The DTC appears to form gap junctions with germ cells at both long external processes and processes that intercalate between germ cells. At this time a second, more proximal focus of somatic innexin expression was sometimes detected. Though this second focus might represent extensions from the DTC, expression of inx-9::gfp suggested that other somatic cells besides the DTC might be involved. By the late L3 stage, the DTC no longer appears to be in contact with all of the germ cells. To better understand the contacts between germ cells and the DTC, we examined early L4-stage animals by TEM. We observed several processes trailing behind the DTC cell body on the outer edge of the germ line, as well as extensions that dig deeply between germ cells. The immunofluorescence results suggest that gap junctions form between the DTC and germ cells at both the outer and inner DTC arms.
• Primary Identifier: Expr11975

8 Anatomy Terms

Definition	Name	Synonym	Primary Identifier
Male haploid germ cell.	sperm	spermatozoa	WBbt:0006798
organ producing either sperm or ova.	gonad		WBbt:0005175
A cell which gives rise to spermatids by meiosis.	spermatocyte		WBbt:0006799
Somatic gonad precursor cell	Z1	lineage name: MSpppaap	WBbt:0004577
Somatic gonad precursor cell	Z4	lineage name: MSappaap	WBbt:0004574
Germ line precursor cell	Z3	lineage name: P4.a	WBbt:0004575
Germ line precursor cell	Z2	lineage name: P4.p	WBbt:0004576
a cell, of either sex, directly concerned in the production of a new organism.	germ cell		WBbt:0006796

3 Genes

WormBase Gene ID	Gene Name	Sequence Name	Organism
WBGene00002136	inx-14	F07A5.1	Caenorhabditis elegans
WBGene00002143	inx-21	Y47G6A.1	Caenorhabditis elegans
WBGene00002144	inx-22	Y47G6A.2	Caenorhabditis elegans

0 Life Stages