31 Developmental Competence of Embryo vis-à-vis Lipopolysaccharide Sujata Jinagal 1,2 , Ravi Dutt 2 , Swati Thakur 1,3 , Meeti Punetha 1 , Maninder Sharma 1 , Sheetal Saini 1 , Suman Chaudhary 1 , Pradeep Kumar 1 , P S Yadav 1 , Dharmendra Kumar 1 * 1 Animal Physiology and Reproduction Division, ICAR-Central Institute for Research on Buffaloes, Hisar-125001, Haryana, India 2 Department of Veterinary Gynaecology and Obstetrics, Lala Lajpat Rai University of Veterinary and Animal Sciences, Hisar, 125004, Haryana, India 3 Department of Veterinary Physiology and Biochemistry, Lala Lajpat Rai University of Veterinary and Animal Sciences, Hisar, 125004, Haryana, India ARTICLE INFO Key Words: Bufalo, Developmental competence, Embryo, Lipopolysaccharide, Oocytes ABSTRACT Post-partum uterine infammation in dairy bovines impairs the reproductive process resulting in extended anestrus, reduced conception and increased pregnancy attrition. Pathogen associated molecular patterns (PAMPs) are a set of molecular motifs that are present on the surface of various classes of microbes. Bacterial lipopolysaccharides (LPSs) are an endotoxin found in the cell membranes of Gram-negative bacteria, are considered as a prototypical class of PAMPs. Among PAMPs, LPS is the most potent one present on the surface of E. coli associated with endometritis and infammation of the uterus. When ovarian follicular cells are exposed to LPS, toll-like receptor (TLR) and cluster of diferentiation 14 (CD14) will be expressed, activating to culminate in the up-regulation of pro-infammatory cytokines like IL-1β, IL-18 and TNF which reacts directly to bacterial products and impairing reproductive functions. Although, both theca interna and granulosa cells are capable of responding to infammatory mediators and altering some functions of the oocytes may result in failure of the oocyte to become fully competent, even if the insult occurs well before ovulation. Several studies have been focused on the efect of LPS on the reproductive performance of dairy animals but the efect of LPS on oocytes during maturation and their development is yet to be defned well. Terefore, the present review emphasized on the efect of LPS on important female reproductive functions and possible mechanism of bacterial endotoxin LPS action on the embryonic development through various pathways. Introduction Bacterial endotoxin known as lipopolysaccharide (LPS) is found in the outer membranes of Gram-negative bac- teria like E. coli and is linked to postpartum endometritis (inflammation of the inner wall of the uterus/endo- metrium) in animals. Cattle and buffalo frequently develop uterine bacterial infections just after parturi- tion (Ghanem et al., 2002; Herath et al., 2007; Parikh et al., 2022) and approximately 20 per cent of animals whose * Corresponding author. E-mail address: dharmendra.kumar@icar.gov.in (Dharmendra Kumar) Received 04.01.2023; Accepted 06.03.2023 Copyright @ Animal Reproduction Update (https://acspublisher.com/journals/index.php/aru) Animal Reproduction Update Year 2023, Volume-3, Issue-1 (January - June) Review article www.acspublisher.com doi: 10.48165/aru.2023.3.1.6