Public and local acts of the Legislature of the State of Michigan.

Printed Detroit : J.S. Bagg (1836)

Magna Britannia; : being a concise topographical account of the several counties of Great Britain. /

Publisher's imprint in v. 6 differs: Printed for Thomas Cadell ... 1822.

Sämmtliche Werke.

Edited by August Wilhelm Bohtz?

Letters of Anna Seward : written between the years 1784 and 1807 : in six volumes.

Folded facsimile letter from the author to Archibald Constable tipped in following p. [xii]

Journal of Daniel Coker, : a descendant of Africa, from the time of leaving New York, in the ship Elizabeth, Capt. Sebor, on a voyage for Sherbro, in Africa, in company with three agents, and about ninety persons of colour. : The Rev. Samuel Bacon, John B. Bankson, Samuel S. Crozer. Agents. : With an appendix.

"Appendix to the Rev. D. Coker's Journal" (pages [41]-52) includes "Letter from Nathaniel Peck to his mother in Baltimore".

The life and adventures of Olaudah Equiano; or Gustavus Vassa, the African. : From an account written by himself. /

"Juvenile books, published by Samuel Wood & Sons, New York.": page [4] of cover.

Caroli a Linné Systema vegetabilium, secundum classes, ordines, genera, species, cum characteribus et differentiis.

Mode of access: Internet.

Georg Christoph Lichtenberg's vermischte Schriften : mit dem Portrait, Facsimile und einer Ansicht des Geburtshauses des Verfassers

Signatur Na 50, Schop 603/408

Meiotic and epigenetic defects in Dnmt3L-knockout mouse spermatogenesis

The production of mature germ cells capable of generating totipotent zygotes is a highly specialized and sexually dimorphic process. The transition from diploid primordial germ cell to haploid spermatozoa requires genome-wide reprogramming of DNA methylation, stage- and testis-specific gene expression, mitotic and meiotic division, and the histone-protamine transition, all requiring unique epigenetic control. Dnmt3L, a DNA methyltransferase regulator, is expressed during gametogenesis, and its deletion results in sterility. We found that during spermatogenesis, Dnmt3L contributes to the acquisition of DNA methylation at paternally imprinted regions, unique nonpericentric heterochromatic sequences, and interspersed repeats, including autonomous transposable elements. We observed retrotransposition of an LTR-ERV1 element in the DNA from Dnmt3L(-/-) germ cells, presumably as a result of hypomethylation. Later in development, in Dnmt3L(-/-) meiotic spermatocytes, we detected abnormalities in the status of biochemical markers of heterochromatin, implying aberrant chromatin packaging. Coincidentally, homologous chromosomes fail to align and form synaptonemal complexes, spermatogenesis arrests, and spermatocytes are lost by apoptosis and sloughing. Because Dnmt3L expression is restricted to gonocytes, the presence of defects in later stages reveals a mechanism whereby early genome reprogramming is linked inextricably to changes in chromatin structure required for completion of spermatogenesis.