The efficacy of recombinant equine follicle stimulating hormone (reFSH) to promote follicular growth in mares using a follicular suppression model.

The efficacy of a recently engineered single chain recombinant equine follicle stimulating hormone (reFSH) was investigated in estrous cycling mares whose gonadotropins and follicular activity had been suppressed by concurrent treatment with progesterone and estradiol (P&E). Time of estrus was synchronized in 15 estrous cycling mares during the breeding season with prostaglandins F(2alpha) (PGF(2alpha)). The day after ovulation, mares were treated once daily with P&E for 14 days. Mares received a second injection of PGF(2alpha) on day 6 of the synchronized estrous cycle to induce luteolysis. On day 8 post-ovulation mares were randomly assigned to three groups: small dose reFSH-treatment group (0.5mg reFSH IV, twice daily); large dose reFSH-treatment group (0.85mg reFSH IV twice daily); control group (saline IV, twice daily). reFSH treatment occurred concurrently with the last week of P&E treatment. After a follicle or cohort of follicles reached 35mm in diameter, mares were injected with 0.75mg of recombinant equine luteinizing hormone (reLH) to induce ovulation. Post-treatment ovulation was assessed. Daily blood samples were collected for analysis of FSH, LH, estradiol, progesterone, and inhibin by radioimmunoassay (RIA). On the first day of reFSH/saline treatment, blood samples were collected periodically from 1h prior to treatment to 6h post-injection via an indwelling jugular catheter to determine acute changes in FSH concentrations. Monitoring of follicular activity, estrus, and ovulation was performed daily by utilizing a stallion and transrectal ultrasonography. A difference (por=35mm follicles (days 16-21) than controls. Mares treated with reFSH, at either dose, took less time (average: 2.95+/-0.42 days) to develop 2-3 times more pre-ovulatory follicles than control mares (7.8+/-0.51 days) (p

Characterization of the breakpoint of a 3.5-kb deletion of the beta-globin gene.

The precise extent and breakpoints of a deletion of the beta-globin gene in a Thai patient have been determined using direct sequencing of a PCR product. This lesion is not detectable by current screening methods using PCR to analyze the beta-globin genes and is, therefore, a potential source of error in the diagnosis and prenatal detection of beta-thalassemia.

The structure of the calmodulin gene of Plasmodium falciparum.

The calmodulin gene and its flanking sequences from the malaria parasite, Plasmodium falciparum, have been analysed. The structure of this gene is unique amongst other known calmodulin genes. It exists as a single copy on chromosome 14 and has a single intron. The nucleotide sequence of this 4-kb region suggests the existence of three transcriptional units, each separated by a highly A+T-rich sequence. Sequences controlling gene expression might be expected to occur in these intergenic regions. The predicted protein sequences suggest that these other genes are transcribed in different orientations. Primer extension studies suggest that calmodulin mRNA has a major start site 62 bases upstream of the initial ATG. The calmodulin gene possesses consensus eukaryotic TATA, CAAT box, polyadenylation and splice junction sequences. This is the first detailed report of the DNA sequence surrounding a housekeeping gene in P. falciparum.

A highly conserved amino-acid sequence in thrombospondin, properdin and in proteins from sporozoites and blood stages of a human malaria parasite.

As a consequence of gene cloning and DNA sequencing several gene families are emerging in the field of cell-cell recognition. These include immunoglobulins, integrins, certain extracellular glycoproteins and a family of functionally unrelated proteins which include factor B. We report here the cloning and sequencing of a gene from Plasmodium falciparum, coding for a protein we call thrombospondin related anonymous protein (TRAP), which shares certain sequence motifs common to other well-characterized proteins. The most significant homology is based around the sequence Trp-Ser-Pro-Cys-Ser-Val-Thr-Cys-Gly (WSPCSVTCG), present in three copies in region I of thrombospondin (TSP), six copies in properdin (P) and one copy in all the circumsporozoite (CS) proteins sequenced so far. TRAP also shares with certain extracellular glycoproteins, including TSP, the cell-recognition signal Arg-Gly-Asp (RGD), which has been shown to be crucial in the interaction of several extracellular glycoproteins with members of the integrin superfamily. Unlike the CS protein, TRAP is expressed during the erythrocytic stage of the parasite life cycle.

Analysis of an inversion within the human beta globin gene cluster.

We have cloned and sequenced the DNA from two regions of the defective beta-globin gene cluster from a patient with Indian A gamma delta beta thalassaemia, and confirmed the complex and unusual pattern of rearrangement involving two separate deletions (0.8 kb and 7.5 kb) the inversion of the 15.5 kb segment separating them, as previously proposed from gene mapping studies [1]. All four breakpoints occur within the transcribed region of the globin genes and at one junction are found six nucleotides of unknown origin. This unique rearrangement results in enhanced expression of the upstream fetal gene, and is therefore is pertinent to the localisation of any putative control region involved in the coordinate expression of fetal and adult genes.