SPT2 chromatin protein domain containing 1
Synonyms: 5830435K17Rik
Strain Symbol: C57BL/6NJ-Spty2d1em1(IMPC)J/Mmjax
Allele Symbol: Spty2d1em1(IMPC)J
Spty2d1 +/- X Spty2d1 +/- intercross results:
| Stage | -/- | +/- | +/+ | Total |
|---|---|---|---|---|
| E9.5 | 19% | 49% | 32% | n = 53 |
| E10.5 | 18% | 61% | 22% | n = 137 |
| E11.5 | 20%* | 57% | 23% | n = 129 |
| E12.5 | 21%** | 57% | 21% | n = 84 |
*At E11.5 approximately 1/3 of the mutant embryos recovered are dying.
**By E12.5 all mutants are either dead or resorbing.
E9.5 Spty2d1-/- embryos are often slightly smaller than their littermates but mainly normal. A minority present with abnormally shaped heads. By E10.5 Spty2d1-/- the majority are small for their litter but normal, a minority have abnormally shaped heads and abnormal blood pooling as in the mutant embryo on the right. By E11.5 a minority of Spty2d1-/- embryos are dying while the majority of those that are alive present with abnormal blood pooling in the heart and in the vasculature/region of the embryo near the heart, as in the two embryos on the right. A minority of mutants have abnormal hearts and pericardial edema, such as the mutant on the right. Although all of the E11.5 mutants are smaller than their littermates, a minority appear normal such as the Spty2d1-/- mutant on the left. At E10.5-11.5, when dissected intact, the yolk sacs appear to have normal vasculature but the vessels are pale when compared with controls. By E12.5 all Spty2d1-/- are dying or resorbing.
At E10.5, the Spty2d1-/- placentas examined exhibit a reduction in the Tpbpa+ spongiotrophoblast (SpT) layer. While the thickness of the Tfeb+ labyrinth trophoblast layer is comparable to controls, elevated Tfeb signal intensity suggests an increased density of Tfeb+ cells.
At E11.5, Spty2d1-/- placentas show a more severe manifestation of the E10.5 defects.
By E12.5, Spty2d1-/- placentas exhibit a severely reduced Tpbpa+ SpT layer, diminished Tfeb+ labyrinth layer, and impaired Gcm1+ chorioallantoic branching.
E10.5 Spty2d1-/- mutants are relatively normal and display regular germ layer features and patterning.
Section in situ hybridization of WT embryos reveals low level Spty2d1 expression (blue/purple) throughout the embryo. This embryo was counterstained with eosin.
Section in situ hybridization of WT placentas with an Spty2d1 anti-sense probe (purple/blue) reveals widespread expression in the fetal compartment of the placenta and appears slightly more highly expressed in the junctional zone than in the labyrinth at both E9.5 and E10.5.
Accession number: NM_175318.4