The study investigated the role of odor cues from two naked mole-rat colonies, in conjunction with behavioral cues from nonbreeding colony members, in maintaining suppression of ovulation in subordinate female naked mole-rats isolated from the two parent colonies. Four high ranking nonbreeding female naked mole-rats were removed from their respective parent colonies and singly housed in separate burrow systems. For a 64-day period, the removed females were maintained in daily odor contact with their parent colony by daily rotating soiled bedding material between the parent colony and the burrow systems of removed females. In addition, subsets of nonbreeding animals from the respective parent colony were regularly moved into the burrow systems of removed females for 2-day periods during this 64-day period. Removed females were therefore in continual social contact with subsets of parent colony animals except for the breeding pair. All four removed females exhibited raised levels of urinary progesterone (< 2 ng/mg Cr) indicative of the onset of ovarian function within 3 days of being separated from the parent colony. Removed females exhibited a normal ovulatory cycle with levels of progesterone remaining elevated for 25-35 days (mean concentration of progesterone +/- SEM; 16.2 +/- 2 ng/mg Cr). Initiation of aggression and sexual behavior by removed females increased significantly when they were isolated from the parent colony. The results demonstrated that odor cues from the complete colony in conjunction with behavioral/tactile/vocal cues from the nonbreeding colony members were not the major cues maintaining reproductive suppression in nonbreeding female naked mole-rats. Instead, our results suggest that female reproductive suppression in naked mole-rats is caused by a dominance-related behavioral mechanism requiring direct contact with the breeding female.

Three transgenic females from a first generation transgenic male were induced to lactate between Il and 12 months of age using a series of estrogen and progesterone injections. The milk contained human longer acting tissue plasminogen activator (LAtPA) at comparable concentrations (1-3 mg/ml) as occurred in the original founder female, In addition, the transgenic male was induced with a hormonal regime and was shown to produce 0.85 mg/ml of LAtPA. Milk protein gels indicated that the milk products (casein, IgG) were essentially normal. These experiments show that expression data for this vector can be evaluated in a shorter period of time in dairy goats than would be required through normal gestation and lactation schedules and can be used to identify the relative expression of transgenes in mammary tissue that would occur during normal lactation.

Mid-ocean ridge basalt (M0RB)-normalized multi-element plots have been used by many authors to identify the thermotectonic environment of the eruption of Early Proterozoic (2500–1600 Ma) volcanic suites by comparison with the characteristic signatures of modern suites. These diagrams are preferred to binary and ternary discriminant diagrams, because they apply to a range of rock types not just basalts, are commonly available in the literature, facilitate visual comparison with the standard suites, allow the examination of numerous inter-element ratios simultaneously, contain petrogenetic information, and can be adequately described in terms of elemental concentrations and ratios. In this chapter, the diagrams have are to compare the trace element compositions of Early Proterozoic volcanics with the average compositions of modern suites compiled from the largest and most complete data sets available. The geochemical data should be supplemented by geological information, when attempting to identify the eruptive environment of Early Proterozoic volcanic rock suites, because of the difficulties in distinguishing chemically between the sequences of continental flood basalts (CFB) and the calcalkaline basalts (CAB) of volcanic arcs.

We report the first successful production of transgenic goats that express a heterologous protein in their milk. The production of a glycosylation variant of human tPA (LAtPA - longer acting tissue plasminogen activator) from an expression vector containing the murine whey acid promoter (WAP) operatively linked to the cDNA of a modified version of human tPA was examined in transgenic dairy goats. Two transgenic goats were identified from 29 animals born. The first animal, a female, was mated and allowed to carry the pregnancy to term. Milk was obtained upon parturition and was shown to contain enzymatically active LAtPA at a concentration of 3-mu-g/ml.

The production of porcine growth hormone (pGH) from novel expression vectors containing the promoter/enhancer elements of the Moloney murine leukemia virus (MLV) LTR or the human cytomegalovirus (CMV) immediate early gene was examined in transgenic swine. Both fusion genes resulted in elevated levels of serum pGH, elevation of insulin‐like growth factor 1 (IGF‐1), and a pronounced decrease in carcass fat deposition. The two viral promoter/enhancer elements were constitutively active in the transgenic swine throughout the life of the animals. In individual swine, the CMV‐pGH transgene was expressed predominantly in the pancreas while the MLV‐pGH transgene was expressed in a wide variety of tissues. These swine were infertile, had insulin resistance, and demonstrated an accelerated form of osteochondritis dissicans. Our results show that excess pGH produces a phenotype identical to that seen in swine expressing heterologous growth hormones, and provides a baseline for assessing the overall efficiency of producing transgenic swine. Furthermore, our data suggests that unregulated pGH production, even at 15 times normal levels and independent of the tissue source, has adverse effects that outweigh the desired reduction in carcass fat deposition in transgenic swine.

This pilot project was designed to optimize the collection and transfer of microinjectable embryos. Does were synchronized with norgestomet (6 mg) ear implants between December 1987 and April 1988. Implants remained for at least 14 d, and does were superovulated with one of the following: Treatment 1, PMSG (1000 IU) 24 h prior to implant removal; Treatment 2, FSH-P (20 mg) over 4 d, beginning 48 h prior to implant removal; or Treatment 3, FSH-P (24 mg) over 3 d, beginning 24 h prior to implant removal. Animals in Treatment 2 were in estrus by 24 h, in Treatment 3 within 36 h, and in Treatment 1 between 24 and 48 h post implant removal. Treatment 2 had the largest number of ovulations (-x=19.8) and the largest collection of both embryos and unfertilized oocytes (-x=13.6). The collection of fertilized embryos was higher in Treatment 3 (-x=5.0) than in Treatment 2 (-x=2.6) or Treatment 1 (-x=2.7). One-cell embryo collection was optimized by collecting 72 to 79 h following implant removal. All embryos were microinjected with 2 to 3 picol of tris-EDTA buffer into the male pronucleus. Of seven recipient does receiving a total of 34 injected embryos, three (43%) maintained pregnancy and six kids were born. These data establish regimens for superovulation/ synchronization and timing of pronuclear embryo collection for dairy goats for the purpose of microinjection.

Tapering a free electron laser (FEL) amplifier to improve extraction after gain saturation can be accomplished by varying both the wiggler period and the wiggler field. This paper considers specific FEL designs and demonstrates the improvement in extraction efficiency that can be achieved by utilizing both variations. Fabrication considerations make a continuously varying wiggler period impractical for long wigglers, and so this technique entails discontinuous steps in the wiggler period. Such steps in wiggler period must be introduced in a manner such that they do not induce steering in the electron beam for reasonable ranges of transverse velocities and energies nor induce a large spread in phase shifts. We discuss such techniques.

Long term observations have been made on primary cultures of a mixed population of cells prepared from embryonic chick heart. Cell dissociation was accomplished by employing dialyzed bacterial collagenase in a balanced salt solution.