Ben F. Koop

Embryonic ε and γ globin genes of a prosimian primate (Galago crassicaudatus): nucleotide and amino acid sequences, developmental regulation and phylogenetic footprints

Sequence analysis of epsilon and gamma genes and encoded globins and high-pressure liquid chromatography analysis of globin compositions in blood hemolysates obtained from embryos, fetuses and adults show that the prosimian primate Galago crassicaudatus expresses its epsilon and gamma genes only embryonically. Since rabbit, mouse and galago all have embryonic gamma genes but simian primates have fetal gamma genes, we conclude that gamma E evolved into gamma F in stem-simians. An elevated non-synonymous substitution rate characterizes this transition. The alignment of epsilon and gamma nucleotide sequences and the parsimoniously reconstructed evolutionary history of these sequences identify several anciently conserved cis-regulatory elements (phylogenetic footprints) important for gamma expression in primates and also cis-mutations which may have been involved in the recruitment of the gamma gene to a fetal program in simian primates.

Primate evolution at the DNA level and a classification of hominoids

SummaryThe genetic distances among primate lineages estimated from orthologous noncoding nucleotide sequences of β-type globin loci and their flanking and intergenic DNA agree closely with the distances (delta T50H values) estimated by cross hybridization of total genomic single-copy DNAs. These DNA distances and the maximum parsimony tree constructed for the nucleotide sequence orthologues depict a branching pattern of primate lineages that is essentially congruent with the picture from phylogenetic analyses of morphological characters. The molecular evidence, however, resolves ambiguities in the morphological picture and provides an objective view of the cladistic position of humans among the primates. The molecular data group humans with chimpanzees in subtribe Hominina, with gorillas in tribe Hominini, orangutans in subfamily Homininae, gibbons in family Hominidae, Old World monkeys in infraorder Catarrhini, New World monkeys in semisuborder Anthropoidea, tarsiers in suborder Haplorhini, and strepsirhines (lemuriforms and lorisiforms) in order Primates. A seeming incongruency between organismal and molecular levels of evolution, namely that morphological evolution appears to have speeded up in higher primates, especially in the lineage to humans, while molecular evolution has slowed down, may have the trivial explanation that relatively small genetic changes may sometimes result in marked phenotypic changes.

Nucleotide sequence and evolution of the Orangutan ε globin gene region and surrounding Alu repeats

SummaryWe have mapped and sequenced the ε globin gene and seven surrounding Alu repeat sequences in the orangutan β globin gene cluster and have compared these and other orangutan sequences to orthologously related human sequences. Noncoding flanking and intron sequences, synonymous sites of α, γ, and ε globin coding regions, and Alu sequences in human and orangutan diverge by 3.2%, 2.7%, and 3.7%, respectively. These values compare to 3.6% from DNA hybridizations and 3.4% from the ωη globin gene region. If as suggested by fossil evidence and “molecular clock” calculations, human and orangutan lineages diverged about 10–15 MYA, the rate of noncoding DNA evolution in the two species is 1.0–1.5×10−9 substitutions per site per year. We found no evidence for either the addition or deletion of Alu sequences from the β globin gene cluster nor is there any evidence for recent concerted evolution among the Alu sequences examined. Both phylogenetic and phenetic distance analyses suggest that Alu sequences within the α and β globin gene clusters arose close to the time of simian and prosimian primate divergence (about 50–60 MYA). We conclude that Alu sequences have been evolving at the rate typical of noncoding DNA for the majority of primate history.

Establishment and characterization of a new human Burkitt's lymphoma cell line (WSU‐BL)

A new human cell line, WSU‐BL, was established from a malignant ascitic fluid occurring in a patient with Burkitts lymphoma. The established line grows in a single‐cell suspension with a doubling time of 19 hours and expresses L3 morphologic features by the French‐American‐British classification. Immunologic study revealed that WSU‐BL cells express IgM‐λ both in the cytoplasm and on the surface and react with monoclonal antibodies to B‐cell antigens (B1, B4, BL3, BL4, HLA‐DR, and common acute lymphoblastic leukemia antigen [CALLA]). These cells are negative for T‐cell and myeloid/monocyte antigens as well as Epstein‐Barr virus nuclear antigen (EBNA). These results suggest that WSU‐BL corresponds to an intermediate stage of B‐cell differentiation. Both fresh tumor and WSU‐BL cells had a hyperdiploid karyotype carrying the 8;14 chromosome translocation. Molecular studies showed that WSU‐BL has a rearrangement of c‐myc proto‐oncogene and expresses c‐myc RNA. Phorbol ester 12‐0‐tetradecanoylphorbol‐13‐acetate (TPA) and interferon‐gamma (IFN‐γ) were able to induce several phenotypic changes on WSU‐BL cells. Two‐dimensional gel electrophoresis of total cellular protein showed that either TPA or IFN‐γ induced both the synthesis or loss of several proteins. Analysis of the protein patterns indicated that some proteins were uniquely responsive to either TPA or IFN‐γ and others were common to both. This cell line should be valuable for future studies of cell proliferation, differentiation, and oncogenesis concerning this neoplasm.