PARENT SESSION
PLATFORM SESSION 3: EMBRYO METABOLISM, DIFFERENTIATION, AND PROGRAMMED CELL DEATH
Chair: Wolf, Don¹, ¹
Co-chair: Livingston, Tracy¹, ¹
Grand Ballroom I-IV
4:30 PM-6:30 PM

(20) DIFFERENTIAL GENE EXPRESSION DURING TROPHOBLASTIC ELONGATION OF PORCINE CONCEPTUSES.

Ross, Jason¹, Ashworth, Morgan¹, Hurst, Amy², Malayer, Jerry², Geisert, Rodney¹, ¹ Dept Animal Science, Stillwater, OK² Dept Physiological Sciences, Stillwater, OK

ABSTRACT- During late peri-implantation development, porcine conceptuses undergo a rapid (2-3 hrs) morphological transformation from a spherical shape to a thin filamentous form greater than 150 mm in length. Elongation of the conceptus is important for establishing adequate placental surface area needed for survival throughout gestation. Genes involved with triggering this unique transition in conceptus development are not well defined. Objective of the present study was to detect genes differentially expressed during conceptus transformation from spherical (8-9 mm) to tubular (15-40 mm) to filamentous (>150 mm) morphology. Spherical, tubular and filamentous conceptuses were flushed from uteri of gilts between days 10 to 12 of gestation. Conceptuses were measured and snap-frozen in liquid nitrogen. Total RNA was extracted from pooled conceptuses of spherical, tubular and filamentous morphologies. Subtractive hybridization was performed with the PCR-Select cDNA Subtraction Kit from Clontech. Forward and reverse subtractions were performed to compare spherical to tubular and tubular to filamentous morphologies. A total of 384 transcripts from the subtracted products were differentially screened to ensure unique expression for each conceptus morphology classification. Of the 384 transcripts screened, 160 that appeared to be uniquely expressed were sequenced and subjected to BLAST to determine identity. A number of mitochondrial gene products were down-regulated during transition from spherical to tubular morphology. Sequences homologous to interleukin-1 beta, heat shock 70kD protein 8, metallopanstimulin 1 and S-adenosylhomocysteine hydrolase were among the transcripts up-regulated during conceptus transition from tubular to filamentous morphology. Utilization of the subtractive hybridization technique provides a method to detect uniquely expressed genes that may be involved with conceptus development and survival.

KEY WORDS: conceptus, pregnancy, pig, development