Brief Summary of Minutes of Annual Meeting

The business meeting was chaired by David Froman using the following outline: (1) a thanks to Jeanna Wilson, (2) leadership options, (3) the importance of participation in annual meetings, (4) the S1020 annual report, and (5) options for the location of the 2008 annual meeting. Dr. Jeanna Wilson was thanked for her finding an excellent venue for the 2007 annual meeting. The locale and accommodations were enjoyed by all. With respect to leadership, the chair inquired as to whether any other member was interested in such service. There was a consensus that David Froman continue to serve as S1020 chair. As such, the chair requested that Doug Rhoads continue to serve as secretary. With respect to the annual meeting, the chair reiterated the importance of complying to email in a timely fashion. This is the means whereby our business and reporting is conducted, timely flow of information enables the timely construction of a meetings agenda, and such a document can be instrumental in attracting key industry participants. With respect to the annual report, the chair encouraged each member to visit the NIMSS website prior to preparing his or her report. The group was reminded that the primary objective of the project is collaboration. Members were asked to format their accomplishments, impact statements, and publications using language and style consistent with website and the projects express experimental goals. The importance of each participants effort in this regard was reinforced remarks from both Winston Hagler and Mark Mirando. The chair requested input by December 15th so that the annual report could be finalized by years end. Three options were considered for the 2008 annual meeting: western North Carolina / eastern Tennessee, the gulf coast in Alabama, and New Orleans. Due to Dan Satterlees projected short-term participation in the project, it seemed reasonable that New Orleans be given priority. The chair agreed to host the meeting on the West Coast should New Orleans prove to be problematic by winter of 2008. The next annual meeting is scheduled for all day on October 30th and the morning of October 31st. This arrangement should afford reasonable time for presentations and minimize meeting expenses.

Countering a long-term decline in the fertility of meat-type chickens Doug Rhoads published his technique outlining a rapid and inexpensive method for isolation of DNA from poultry tissue samples. This advance  along with a full genome evaluation for single nucleotide polymorphisms (SNPs) -- sets the stage for genomic analysis of male chickens characterized with one of two distinct phenotypes known to limit male fertility. In other words, the capability now exists to discover chromosomal regions to be used as quantitative trait loci (QTLs) for semen quality. Doug Rhoads and David Froman obtained an industry award for this purpose. Their point of application will be pedigree line broiler breeder males. Doug Rhoads continued his study of novel RNAs within the chicken reproductive tract. Many of these RNAs appear to be non-coding, polyadenylated gonad-specific RNAs whose appearance within male and female poultry is coincident with onset of meiosis. Historically, gametogenesis has been described in terms of hormone signaling within the hypothalamo-pituitary-gonadal axis. However, the discovery of novel RNAs may enable description of gametogenesis in terms of the interplay between hormones and gonadal gene networks. Fertility in meat-type chickens is, in part, determined by effective copulation. To date, male physical well-being, social dominance, male age and experience, as well as cryptic female choice have been identified as contributing variables. Consequently, a pilot study conducted by the Kuenzel laboratory was significant in that a link was sought between neural structures and male sexual behavior. Specifically, males were characterized as aggressive or non-aggressive based upon their mating behavior. Thereafter, the following variables were measured: fertility, blood plasma testosterone, and immunostaining for gonadotropin releasing hormone 1 (GnRH-1) along with arginine vasotocin (AVT) within selected neural structures. Initially, aggressive males were subfertile and had lower blood plasma testosterone in comparison to non-aggressive males. However, this effect was not independent of time. AVT immunostaining may prove to be a more useful variable that blood plasma testosterone because a significant positive correlation was found (r =0.81) between AVT fiber density within the lateral septum and mounting attempts. In contrast, no difference was observed with respect to the density of GnRH-1 neurons within the bed nucleus of the pallial commissure, the primary nucleus in which GnRH-1 neurons are located. Dan Satterlees quail model continues to provide interesting insights between the responsiveness of the hypothalamo-pituitary-adrenal axis and reproductive performance. Specifically, genetic selection for exaggerated hypothalamic-pituitary-adrenal responsiveness within a high stress line quail (HS) yields dams whose male offspring are characterized by diminished reproductive capacity as evidenced by secondary sexual characteristics and testis weight. Thus, the status of a dams hypothalamo-pituitary-adrenal axis has been shown to affect the reproductive potential of female and male offspring alike. This effect is attributed to transmission of the lipid-soluble stress hormone corticosterone from the dam into the yolk of the egg from which a chick develops. Male mating behavior was also found to differ between HS and low stress (LS) lines as evidenced by a two-way choice test. Based upon direction of first travel, affiliation preference, and time spent near a female, sexually mature but naïve LS males preferred an LS hen as a companion  as did comparable HS males. In contrast, more time was spent near HS females when male test subjects were produced by dams implanted with corticosterone. This effect was observed with treated hens from both the LS and HS lines. In review, the collective work of David Froman, Doug Rhoads, and Dan Satterlee is enabling new insights into the effect of genes on reproductive potential. Likewise, the collective work of Wayne Kuenzel and Dan Satterlee is enabling new questions to be asked about the effect of gene-environment interaction reproductive potential. However, reproductive potential can also be affected by dietary factors  sometimes in an unexpected and uncontrolled manner. In this regard, research conducted by Judy Grizzle and Wallace Berry addressed T-2 toxin detoxification and effects of phytoestrogens, respectively. Molds are ubiquitous in nature and the extent to which mycotoxins contaminate grain crops is difficult to control. Judy Grizzle investigated a potential intervention strategy for trichothethene poisoning. The enzyme 3-O-acetyltransferase can acetylate T-2 toxin and thereby appreciably reduce toxicity. The efficacy of this approach was tested in vitro by exposing chicken macrophages to levels of T-2 toxin comparable to those found within field grains. Macrophages were unaffected when co-incubated with 1 nM purified 3-O-acetyltransferase and then challenged with 200 nM T-2 toxin. The protective effect of the enzyme was lost when macrophages were exposed to a 10-fold increase in T-2 toxin even though the enzymes concentration was increased to 5 nM. Field studies will follow. As evidenced by collaborative work with Dan Satterlee, low level mycotoxin contamination of feed is expected to exacerbate the poor reproductive performance of males characterized by elevated blood corticosterone. Unlike mycotoxins, phytoestrogens are inherent to poultry diets. For example, chickens of all ages are exposed to relatively potent estrogenic isoflavones by virtue of eating a soy-based diet. Previous work from Wallace Berrys laboratory confirmed genistein as the principal soybean isoflavone with the potential to affect chick oviduct development. Therefore, an experiment was performed testing the effect of genistein on traits subject to estrogen. Day-old female chicks were fed a diet in which dried egg white served as the protein source. This eliminated any confounding effect from dietary genistein. Sesame oil and diethylstilbesterol served as negative and positive controls. All experimental compounds were administered daily by gavage to one group of chicks and by subcutaneous injection to another. The presence of genistein within blood plasma was confirmed by HPLC. The estrogenic effect of diethylstilbesterol was mimicked by genistein as both compounds increased oviduct weight as a percentage of body weight, induced hepatic vitellogenin synthesis, and altered behavior. In summary, should bloodstream genistein concentration reach a threshold, then brain and liver functions are subject to the effect of phytoestrogen as is oviduct development. Discovering the basis for photorefractoriness in turkeys James Millam used double-label immunochemistry to document the appearance of proteins within the turkey hens tuberal hypothalamus in response to photostimulation. In general, brain tissue is a mixture of neurons  or bundles of their axons that project towards neurons at other sites within the brain or spinal cord  and glial cells. The proteins induced by photostimulation are known collectively as fos-related antigens (FRA) in which fos- pertains to the gene c-fos. The expression of FRA was largely restricted to cells that also expressed glial acidic fibrillary protein (GFAP), which serves as a marker for glial cells such as astrocytes and tanycytes. Fos-related antigens do not appear within the hypothalamus of photorefractory turkeys. Therefore, the GFAP-positive cells comprise a neurological locus of failure in photorefractoriness. Related experimentation entailed the localization of the enzyme deiodinase II in newly photostimulated turkey hens. As evidenced by immunohistochemistry, deiodinase II co-localized with staining for FRA and GFAP. The significance of this discovery can be explained as follows. A critical signal within the hypothalamo-pituitary-gonadal axis is gonadotropin releasing hormone (GnRH). This neuropeptide is secreted from hypothalamic neurons, enters the bloodstream, and then acts downstream on cells within the pituitary gland. Deiodinase II is required for the conversion of the prohormone tetraiodothyronine to the active hormone triiodothyronine. Thus, within a few hours of exposure to long day length, local production of triiodothyronine induces production of growth factors that ultimately lead to the retraction of glial end-feet. These end-feet cover the ends of axons from which GnRH is secreted. In other words, the triiodothyronine signal serves to remove a physical barrier that may limit entry of GnRH into the bloodstream. Moreover, immunoreactivity to deiodinase II was absent from the rostral and central regions of the tuberal hypothalamus in photorefractory hens. In summary, cessation of egg production in photorefractory hens can now be traced back to the failure of deioidinase II to appear within GFAP-positive cells within the tuberal hypothalamus. As explained above, long day length and thyroid hormones are required for egg production in the turkey. However, these factors are also linked with programming for photorefractoriness, which serves to limit egg production. Programming for photorefractoriness is believed to occur soon after onset of photostimulation. Tom Siopes and James Millam explored the possibility that thyroid hormones serve to enable programming for photorefractoriness. This experiment was performed by treating hens with propylthiouracil for 12 weeks following photostimulation. As evidenced by the concentration of thyroid hormones in the bloodstream of treated and control hens, propylthiouracil was efficacious as an anti-thyroid agent. As expected, egg production commenced once hens were no longer treated with propylthiouracil. However, the pattern at which the egg production of treated hens declined with time was comparable to that of control hens. Therefore, thyroid hormones do not appear to be essential for programming for photorefractoriness during the first 12 weeks of photostimulation.

Bailes, S., J. Devers, J. D. Kirby, and D. D. Rhoads. 2007. An inexpensive, simple protocol for DNA isolation from blood for high throughput PCR or restriction endonuclease-based genotyping. Poult. Sci. 86:102-106. Lábaque, M. C., D. G. Satterlee, D. A. Guzman, and R. H. Marin. 2007. Ontogeny of the cloacal gland in male Japanese quail classified in a T-maze. Poult. Sci. 86:2013-2119. Madison, F. N., A Jurkevich, and W. J. Kuenzel. 2007. Sex differences in plasma corticosterone release in undisturbed chickens (Gallus gallus) in response to arginine vasotocin and corticotrophin releasing hormone. Gen. Comp. Endocrinol. (in press), available on line:doi:1016/j.ygen.2007.08.014. Perrin, S. L., J. Lin, and J. M. Grizzle. 2007. The iosolation and purification of tricothethene 3-O-acetyltransferase for protection against T-2 toxin. Department of Animal Science Research Report, University of Tennessee. http://animalscience.ag.utk.edu/pdf/Reports/2007/IsolationPurification-SLP-JL.pdf Satterlee, D. G., C. A. Cole, and S. A. Castille. 2007. Maternal corticosterone further reduces the reproductive function of male offspring hatched from eggs laid by quail hens selected for exaggerated adrenocortical stress responsiveness. Poultry Sci. 86: 572-581. Satterlee, D. G., M. Tong, S. A. Castille, and R. H. Marin. 2007. Cloacal gland growth differences in high and low plasma corticosterone stress response line male quail reared under short daylengths. Poultry Sci. 86: 1213-1217. Siopes, T. D. 2007. Lighting for summer egg production in turkeys: Day length and light intensity. Poult. Sci. 86:2413-2419.