We have constructed a zebrafish genetic linkage map consisting of 705 simple sequence-length polymorphism markers (SSLPs). The map covers 2350 centimorgans (cM) of the zebrafish genome with an average resolution of 3.3 cM. It is a complete map in genetic mapping terms (there is one linkage group for each of the 25 chromosomes), and it has been confirmed by somatic-cell hybrids and centromere-mapping using half-tetrad analysis. The markers are highly polymorphic in the zebrafish strains used for genetic crosses and provide a means to compare genetic segregation of developmental mutations between laboratories. These markers will provide an initial infrastructure for the positional cloning of the nearly 600 zebrafish genes identified as crucial to vertebrate development,and will become the anchor for the physical map of the zebrafish genome.

We report the construction of the first complete genetic linkage map of the laboratory rat. By testing 1171 simple sequence length polymorphisms (SSLPs), we have identified 432 markers that show polymorphisms between the SHR and BN rat strains and mapped them in a single (SHR x BN) F2 intercross. The loci define 21 large linkage groups corresponding to the 21 rat chromosomes, together with a pair of nearby markers on chromosome 9 that are not linked to the rest of the map. Because 99.5% of the markers fall into one of the 21 large linkage groups, the maps appear to cover the vast majority of the rat genome. The availability of the map should facilitate whole genome scans for genes underlying qualitative and quantitative traits relevant to mammalian physiology and pathobiology.

Survivors reported few cancer-related problems with only a small subset reporting problems in adjustment. Although differences were small, younger cancer survivors reported significantly worse adaptation than older survivors. Much of the adaptation to having had cancer may have already occurred in long-term survivors.

HighlightsTwin pregnancy with complete hydatidiform mole and co-existing normal live fetus is rare.Antenatal and postpartum complications such as gestational trophoblastic neoplasia are common.Patients require close clinical monitoring and urgent delivery in the setting of complications.Follow-up with serum β-HCG is important for the diagnosis of persistent trophoblastic disease.

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