52 GREATER PHENOTYPIC VARIABILITY IN CLONED CATTLE FETUSES FROM ONE CELL LINE THAN CONTEMPORARY HALF-SIBS GENERATED BY ARTIFICIAL INSEMINATION OR IN VITRO EMBRYO PRODUCTION
Notice bibliographique
Résumé
The cloning of cattle by somatic cell nuclear transfer (NT) is associated with considerable variation in developmental abnormalities. Some of this variation may be due to the cell types/lines used and the specific production and culture methods for NT embryos. Fetal and placental development were studied in 24 pregnancies generated by NT (Wells et al., 2003 Theriogenology 59, 45–59) from a granulosa cell line. The controls consisted of 11 and 14 pregnancies resulting from in vitro-produced embryos (IVP) and artificial insemination (AI), respectively. All fetuses shared the same Friesian sire; oocytes for the derivation of NT or IVP embryos were obtained from abattoir-derived ovaries of Friesian cows. Morphometric measurements were made on the fetuses, fetal membranes, fluid volumes and placentomes at Days 50, 100 and 150 of gestation after slaughter. Pairwise comparisons of within group variances between the treatment groups were made using the F-test. The pregnancy loss from AI or embryo transfer to Day 150 was ~40% for the AI and IVP groups. However, 60% of NT embryos transferred had been lost by Day 150. NT fetal weights at Day 100 were more variable than for the AI (P < 0.001) and IVP (P < 0.05) groups. The NT crown-rump lengths were also more variable compared with the IVP (P < 0.05) but not the AI group. At Day 100, NT heart (P < 0.01), kidney (P < 0.01) and liver (P < 0.05) weights were more variable compared with the AI group; both liver (P < 0.05) and kidney (P < 0.01) weights were similarly more variable in the Day 150 NT group. Part of this variability may be due to disproportionate organ growth in NT fetuses. Increased variability was most evident in the utero-placental tissues. At Day 50, the total fetal membrane weights were more variable in the NT compared with the AI (P < 0.001) but not the IVP group. The Day 50 IVP membrane weights were also more variable (P < 0.05) than for the AI group. The greater variability of the Day 150 NT membrane weights, when compared with AI (P < 0.05) or IVP (P < 0.01), could be due partly to greater variation in the allantoic and amniotic fluid volumes. Placentome numbers were significantly lower in the surviving Day 100 NT pregnancies but the weights of the total maternal caruncular tissue of the placentomes were significantly higher and more variable in the NT group (P < 0.05 for both AI and IVP). Placentome numbers in surviving NT pregnancies at Day 150 were similar to the controls. However, the total caruncle weights in both the NT and IVP groups were more variable when compared with the AI group (P < 0.05 for both). Thus, there is greater variability in fetal membrane and placental development in NT and, to a certain extent, IVP fetuses, when compared with the AI group. The increased variability within this NT group suggests that epigenetic effects arising from incomplete reprogramming of the donor genome and embryo culture can override genetic traits to a certain extent. Supported by FRST C10X0018.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,002 | 0,001 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,001 | 0,000 |
| Bibliométrie | 0,000 | 0,001 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,000 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule tête enseignante, pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».