Stevens L C
Results Probl Cell Differ. 1980;11:265-74. doi: 10.1007/978-3-540-38267-6_34.
Teratomas are rare in most strains of mice. Testicular teratomas are common in some sublines of inbred strain 129. Ovarian teratomas are common in inbred strain LT. Testicular teratomas are derived from primordial germ cells and can be experimentally produced by grafting 121/2-day genital ridges to the testes of adults. They develop into testes and for some strains most have teratomas. Ovarian teratomas are derived from parthenogenetically activated ovarian oocytes that have completed the first meiotic division. Teratomas of either sex can be experimentally produced by grafting early embryos to various sites in adults. Embryo-derived teratomas originate directly from undifferentiated embryonal cells. Occasionally teratomas are malignant (teratocarcinomas) and can be maintained as transplantable tumors. Some form embryoid bodies that resemble normal early embryos. When the stem cells of some transplantable teratocarcinomas are injected into blastocysts and transferred to the uteri of pseudopregnant females, they participate in normal development and contribute to the formation of all major tissues including functional sperm and eggs. Spontaneous parthenogenesis is common in strain LT oocytes after ovulation. The eggs cleave, form blastocysts which implant in the uterus, but after the egg cylinder stage they become disorganized and are aborted. Eight-cell embryos from the pigmented LT strain were aggregated with embryos of albino strain 129 and transferred to the uteri of pseudopregnant females. They participated in development and contributed to the formation of normal chimeric tissues. Offspring from eggs derived from parthenogenetic embryonal cells were produced, demonstrating that parthenogenetic embryonic cells are totipotent. It is still a mystery why parthenogenetic embryos will not survive in utero.
畸胎瘤在大多数小鼠品系中较为罕见。睾丸畸胎瘤在近交系129的某些亚系中很常见。卵巢畸胎瘤在近交系LT中很常见。睾丸畸胎瘤起源于原始生殖细胞，可通过将12.5天的生殖嵴移植到成年小鼠的睾丸中实验性产生。它们发育成睾丸，对于某些品系来说，大多数会形成畸胎瘤。卵巢畸胎瘤源自孤雌生殖激活的、已完成第一次减数分裂的卵巢卵母细胞。通过将早期胚胎移植到成年动物的不同部位，可实验性产生两性的畸胎瘤。胚胎来源的畸胎瘤直接起源于未分化的胚胎细胞。偶尔，畸胎瘤是恶性的（畸胎癌），可作为可移植肿瘤维持生长。有些会形成类似正常早期胚胎的胚状体。当将一些可移植畸胎癌的干细胞注入囊胚并转移到假孕雌性动物的子宫中时，它们会参与正常发育，并有助于形成包括功能性精子和卵子在内的所有主要组织。排卵后，自发孤雌生殖在LT品系的卵母细胞中很常见。卵子分裂，形成植入子宫的囊胚，但在卵柱期后它们会变得紊乱并流产。将有色LT品系的八细胞胚胎与白化病品系129的胚胎聚集在一起，并转移到假孕雌性动物的子宫中。它们参与发育并有助于形成正常的嵌合组织。产生了源自孤雌生殖胚胎细胞的卵子的后代，这表明孤雌生殖胚胎细胞是全能的。孤雌生殖胚胎为何无法在子宫内存活仍是个谜。
