87 VARIATION IN HEMATOLOGICAL PROFILES BETWEEN BOVINE SOMATIC CELL NUCLEAR TRANSFER CLONES AND CONTEMPORARIES FROM BIRTH TO ADULTHOOD

Abstract

The hematological characterization of clones derived by somatic cell nuclear transfer (SCNT) has not been extensively reported. Studies show that, generally, hematological parameters are within normal ranges, although distinct divergence between specific cohorts of clones and contemporaries exist. The aim of this study was to identify similarities and differences between cohorts of bovine clones and control animals and analyze the variations over time as the collective cohorts mature. Hematological profiles of 47 clones derived from 4 cell lines and 23 of their age- and sex-matched contemporary controls were compared. These donor cell lines were from 2 beef (male, n = 30) and 2 dairy (1 male, n = 9 and 1 female, n = 8) breeds and derived from myogenic cells, skin fibroblasts, and granulosa cells. Matched contemporaries, analyzed as one group, were produced via natural mating (n = 5) and AI (n = 14), with an additional in vitro-produced (IVP) group (n = 4) in the female cohort. All animals were subjected to similar management, nutrition, and environmental conditions. Serial samples were collected from birth until 15 months. Samples were assessed for the standard hematological parameters and cell morphology by a commercial clinical lab. Parameters were analyzed by one-way or as repeated measures ANOVA. The mean values for erythroid, myeloid, and lymphoid parameters were within normal ranges for both SCNT and controls, indicative of normal physiology. Red blood cells (RBC) from SCNT and control calves showed anisocytosis, poikilocytosis, cell fragmentation, and stippling, with a greater prevalence found in SCNT than in the controls. These abnormal morphologies were still evident in SCNT animals at 15 months of age, suggestive of delayed or incomplete erythroid maturation. Numbers of RBC, mean corpuscular volume (MCV), and hemoglobin (MCH) were different (P < 0.0001) between the collective SCNT cohorts and control animals over time, irrespective of genetics, sex, or breed. Taken together, these data suggest that erythropoiesis is generally perturbed in SCNT animals. In beef SCNT lines, platelet numbers were consistently different (P < 0.0001) from controls. White blood cell counts (WBC) were greater (P < 0.05) collectively in SCNT, although within the normal range, and the differential WBC changed with age (P < 0.05). Lymphocyte counts were greater (P < 0.05) in the collective SCNT cohorts. Further differences were seen in myeloid counts between specific SCNT and control cohorts. The greater variance evident in the myeloid parameters of SCNT animals was presumably because of an increased incidence of transient infections or inflammation in these animals. In summary, although most parameters were within the normal ranges over time, SCNT animals commonly display altered RBC, MCV, MCH, WBC, and lymphocyte parameters, which may be linked to cloning per se. This could partially explain the greater susceptibility of SCNT animals to external stressors.

Supported by FRST contract C10X0311 and NRCGD.