Type XIII collagen is a type II transmembrane protein found at sites of cell adhesion. Transgenic mouse lines were generated by microinjection of a DNA construct directing the synthesis of truncated alpha1(XIII) chains. Shortened alpha 1(XIII) chains were synthesized by fibroblasts from mutant mice, and the lack of intracellular accumulation in immunofluorescent staining of tissues suggested that the mutant molecules were expressed on the cell surface. Transgene expression led to fetal lethality in offspring from heterozygous mating with two distinct phenotypes. The early phenotype fetuses were aborted by day 10.5 of development due to a lack of fusion of the chorionic and allantoic membranes. The late phenotype fetuses were aborted by day 13.5 of development and displayed a weak heartbeat, defects of the adherence junctions in the heart with detachment of myofilaments and abnormal staining for the adherence junction component cadherin. Decreased microvessel formation was observed in certain regions of the fetus and the placenta. These results indicate that type XIII collagen has an important role in certain adhesive interactions that are necessary for normal development.
Abortion, particularly later-term abortion, and neonaticide, selective non-treatment of newborns, are feasible management strategies for fetuses or newborns diagnosed with severe abnormalities. However, policy varies considerably among developed nations. This article examines abortion and neonatal policy in four nations: Israel, the US, the UK and Denmark. In Israel, late-term abortion is permitted while non-treatment of newborns is prohibited. In the US, on the other hand, later-term abortion is severely restricted, while treatment to newborns may be withdrawn. Policy in the UK and Denmark bridges some of these gaps with liberal abortion and neonatal policy. Disparate policy within and between nations creates practical and ethical difficulties. Practice diverges from policy as many practitioners find it difficult to adhere to official policy. Ethically, it is difficult to entirely justify perinatal policy in these nations. In each nation, there are elements of ethically sound policy, while other aspects cannot be defended. Ethical policy hinges on two underlying normative issues: the question of fetal/newborn status and the morality of killing and letting die. While each issue has been the subject of extensive debate, there are firm ethical norms that should serve as the basis for coherent and consistent perinatal policy. These include 1) a grant of full moral and legal status to the newborn but only partial moral and legal status to the late-term fetus 2) a general prohibition against feticide unless to save the life of the mother or prevent the birth of a fetus facing certain death or severe pain or suffering and 3) a general endorsement of neonaticide subject to a parent's assessment of the newborn's interest broadly defined to consider physical harm as well as social, psychological and or financial harm to related third parties. Policies in each of the nations surveyed diverging from these norms should be the subject of public discourse and, where possible, legislative reform.