Conceptus estrogen and prostaglandins provide the maternal recognition of pregnancy signal to prevent luteolysis during early pregnancy in the pig†.

Conceptus estrogens and prostaglandins have long been considered the primary signals for maternal recognition of pregnancy (MRP) in the pig. However, loss-of-function studies targeting conceptus aromatase genes (CYP19A1 and CYP19A2) and prostaglandin-endoperoxide synthase 2 (PTGS2) indicated that conceptuses can not only signal MRP without estrogens or prostaglandins but can maintain early pregnancy. However, complete loss of estrogen production leads to abortion after day 25 of gestation.

Maternal recognition of pregnancy in the pig: A servomechanism involving sex steroids, cytokines and prostaglandins.

Maternal recognition of pregnancy (MRP) is a term utilized in mammals to describe pathways in which the conceptus alters the endometrial environment to prevent regression of corpora lutea to ensure continued production of progesterone (P4) required for establishment and maintenance of pregnancy. For nearly 40 years after publication of the endocrine/exocrine theory, conceptus estrogen (E2) was considered the primary maternal recognition signal in the pig. Conceptus production of prostaglandin E2 (PGE2) was also considered to be a major factor in preventing luteolysis.

Susceptibility of northern corn rootworm (Diabrotica barberi) populations to Cry3Bb1 and Gpp34/Tpp35Ab1 proteins in seedling and diet overlay toxicity assays.

The northern corn rootworm, Diabrotica barberi Smith & Lawrence (Coleoptera: Chrysomelidae) is a major pest of maize in the United States Corn Belt. Recently, resistance to Bacillus thuringiensis (Bt) maize was reported in North Dakota and increased use of Bt maize hybrids could facilitate resistance evolution in other maize-producing states. In this study, susceptibility to Bt proteins was evaluated in wild D.

Host search behaviors of specialist and generalist root feeding herbivores (Diabrotica spp.) on host and non-host plants.

Western, northern, Mexican, and southern corn rootworms (WCR, NCR, MCR, and SCR) are serious corn pests. We evaluated host search behavior of these pests on six plant species using a video tracking system. After a 5-min exposure to plant roots, behavioral parameters were automatically recorded and used to quantify the search behavior.

Porcine-specific expression of the three functional CYP19 paralogs in early conceptus, placenta, and gonads.

In Brief: Aromatase catalyzes the synthesis of estrogens and has been shown to have an important role during the establishment of pregnancy in the pig. This study confirmed the differential expression of the three aromatase isoforms.

Abstract: Although three porcine aromatase isoforms have been identified, their gene expression profiles in reproduction are still poorly understood.

An improved bioassay for the testing of entomopathogenic nematode virulence to the western corn rootworm (Diabrotica virgifera virgifera) (Coleoptera: Chrysomelidae): with focus on neonate insect assessments.

Bioassays involving newly hatched larval insects can be limited by the larvae's feeding state. Assays attempting to monitor mortality effects can be negatively affected by starvation effects on the larvae. Neonate western corn rootworms have significant reductions in viability if not provided food within 24 h post hatch.

Maize Inbred Mp708 is Highly Susceptible to Western Corn Rootworm, Diabrotica virgifera virgifera (Coleoptera: Chrysomelidae), in Field and Greenhouse Assays.

The western corn rootworm (WCR), Diabrotica vifgirera virgifera LeConte, (Coleoptera: Chrysomelidae) causes significant economic damage in corn production each year. Resistance to insecticides and transgenic corn with Bacillus thuringiensis (Bt), Berliner toxins have been reported throughout the United States Corn Belt. Corn breeding programs for natural resistance against WCR larvae could potentially assist in rootworm management.

Improvements in pig agriculture through gene editing.

Genetic modification of animals via selective breeding is the basis for modern agriculture. The current breeding paradigm however has limitations, chief among them is the requirement for the beneficial trait to exist within the population. Desirable alleles in geographically isolated breeds, or breeds selected for a different conformation and commercial application, and more importantly animals from different genera or species cannot be introgressed into the population via selective breeding.

Gene editing provides a tool to investigate genes involved in reproduction of pigs.

CRISPR-Cas9 gene editing technology provides a method to generate loss-of-function studies to investigate, in vivo, the specific role of specific genes in regulation of reproduction. With proper design and selection of guide RNAs (gRNA) designed to specifically target genes, CRISPR-Cas9 gene editing allows investigation of factors proposed to regulate biological pathways involved with establishment and maintenance of pregnancy. The advantages and disadvantages of using the current gene editing technology in a large farm species is discussed.

Implantation and Placentation in Ruminants.

In comparison to many other mammalian species, ruminant ungulates have a unique form of placentation. Ruminants initially display an epitheliochorial type of placentation; however, during the period of placental attachment, trophoblast giant binucleate cells (BNC) develop within the chorion to migrate and fuse with the uterine surface epithelium to form syncytial plaques. Binucleate cell migration and fusion continues throughout pregnancy but never appears to breach the basal lamina, beneath the uterine surface or luminal epithelium.

Mammalian Placentation: A Tribute to E.C. Amoroso's Contributions to Placenta Development.

Establishment of viviparity in mammals evolved through not only the long-term retainment of the fetus within the maternal uterus but differentiation and expansion of cell layers to form functional membranes to exchange O/CO and nutrients between the placenta and maternal circulations. Development of a fetal placental vascular circulation to interact with the maternal uterus is critical to the survival of all species. However, the fascination with the mammalian placenta is the robust variation in types, form, attachment, invasiveness, structure, cell differentiation, endocrine function, and regulation of the maternal immune system.

Conceptus interferon gamma is essential for establishment of pregnancy in the pig†.

Establishment and maintenance of pregnancy in the pig is a complex process that relies on conceptus regulation of the maternal proinflammatory response to endometrial attachment. Following elongation, pig conceptuses secrete interferon gamma (IFNG) during attachment to the endometrial luminal epithelium. The objective here was to determine if conceptus production of IFNG is important for early development and establishment of pregnancy.

Characterization of Thermal and Time Exposure to Improve Artificial Diet for Western Corn Rootworm Larvae.

The western corn rootworm (WCR), LeConte, is the most serious pest of maize in the United States. In pursuit of developing a diet free of antibiotics for WCR, we characterized effects of thermal exposure (50-141 °C) and length of exposure on quality of WCRMO-2 diet measured by life history parameters of larvae (weight, molting, and survival) reared on WCRMO-2 diet. Our results indicated that temperatures had non-linear effects on performance of WCRMO-2 diet, and no impacts were observed on the length of time exposure.

Development of a nondiapausing strain of northern corn rootworm with rearing techniques for both diapausing and nondiapausing strains.

The northern corn rootworm, Diabrotica barberi Smith & Lawrence, has a univoltine life cycle that typically produces one generation a year. When rearing the northern corn rootworm in the laboratory, in order to break diapause, it is necessary to expose eggs to a five month cold period before raising the temperature. By selective breeding of the small fraction of eggs that hatched without cold within 19-32 days post oviposition, we were able to develop a non-diapausing colony of the northern corn rootworm within five generations of selection.

Disrupting porcine glutaminase does not block preimplantation development and elongation nor decrease mTORC1 activation in conceptuses†.

Elongation of pig conceptuses is a dynamic process, requiring adequate nutrient provisions. Glutamine is used as an energy substrate and is involved in the activation of mechanistic target of rapamycin complex 1 (mTORC1) during porcine preimplantation development. However, the roles of glutamine have not been extensively studied past the blastocyst stage.

Gene editing to investigate the role of conceptus factors in the establishment of pregnancy in the pig.

Development of viviparity in mammals requires that the placenta evolves as an intermediate interface between the fetus and maternal uterus. In addition to the retention of the fetus and secretion of nutrients to support growth and development to term, it is essential that viviparous species modify or inhibit the maternal immune system from recognizing the semi-allogeneic fetus. Following blastocyst hatching from its zona pellucida, trophoblast differentiation provides the initial communication to the maternal endometrium to regulate maintenance of progesterone production from the corpus luteum and biological pathways in uterine and conceptus development necessary in the establishment and maintenance of pregnancy.

Ablation of conceptus PTGS2 expression does not alter early conceptus development and establishment of pregnancy in the pig†.

Pig conceptuses secrete estrogens (E2), interleukin 1 beta 2 (IL1B2), and prostaglandins (PGs) during the period of rapid trophoblast elongation and establishment of pregnancy. Previous studies established that IL1B2 is essential for rapid conceptus elongation, whereas E2 is not essential for conceptus elongation or early maintenance of the corpora lutea. The objective of the present study was to determine if conceptus expression of prostaglandin-endoperoxide synthase 2 (PTGS2) and release of PG are important for early development and establishment of pregnancy.

Optimizing Egg Recovery From Wild Northern Corn Rootworm Beetles (Coleoptera: Chrysomelidae).

The northern corn rootworm, Diabrotica barberi Smith & Lawrence (Coleoptera: Chrysomelidae), is one of the most important insect pests in the U.S. Corn Belt.

Altering rat sexual behavior to teach hormonal regulation of brain imprinting.

In this teaching laboratory, students design and perform an experiment to determine estrogen's role in imprinting the brain of neonatal rats to express either male or female sexual behavior. A discussion question is provided before the laboratory exercise in which each student is asked to search the literature and provide written answers to questions and to formulate an experiment to test the role of estrogen in imprinting the mating behavior of male and female rats. Students discuss their answers to the questions in laboratory with the instructor and design an experiment to test their hypothesis.

Effects of Cold Storage on Nondiapausing Eggs of the Western Corn Rootworm (Coleoptera: Chrysomelidae).

Western corn rootworm, Diabrotica virgifera virgifera LeConte, became much easier to research with the development of a nondiapausing rootworm strain. In the event that the eggs cannot be used immediately researchers have been known to delay egg hatch by storing the eggs at low temperatures. It is not well known how this technique could affect egg hatch or larval development, which could alter the results of an experiment.

Reproduction in domestic ruminants during the past 50 yr: discovery to application.

The study of reproductive physiology in domestic ruminants has progressed from the whole animal to the molecular level in an amazingly short period of time. The volume of information on this subject is enormous; therefore, we have focused on domestic ruminants, with an emphasis on cattle. To date, artificial insemination (AI) is perhaps the most powerful technique that reproductive physiologists and geneticists have provided the livestock industry for genetic improvement.

Comparative Assessment of Four Steinernematidae and Three Heterorhabditidae Species for Infectivity of Larval Diabrotica Virgifera Virgifera.

Larval Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae) were exposed to seven different entomopathogenic nematode species to test their potential infectivity in a laboratory setting. Known D. virgifera-infecting nematode species Heterorhabditis bacteriophora Poinar, Heterorhabditis megidis Poinar, Jackson & Klein, Steinernema feltiae Filipjev, and Steinernema carpocapsae Weiser were tested in a concerted experiment alongside Steinernema diaprepesi Nguyen & Duncan, Steinernema riobrave Cabanillas, Poinar & Raulston, and a Missouri wild-type H.