1. Spermatogenesis, DNA damage and DNA repair mechanisms in male infertility 
Sezgin Gunes, Maha Al-Sadaan, Ashok Agarwal 
Reproductive BioMedicine Online 
Volume 31, Issue 3, Pages (September 2015)
DOI: /j.rbmo
Copyright © 2015 Reproductive Healthcare Ltd. Terms and Conditions

2. Figure 1
DNA replication fork. A view of the arrangement of the replication proteins at the replication fork is shown. Several enzymes and proteins are involved in replication process of genome. Accurate duplication of genetic material is important for both somatic and germ cells and is carried out by polymerase enzymes. SSBP = single-stranded DNA-binding proteins.
Reprinted with permission, Cleveland Clinic Center for Medical Art & Photography © All Rights Reserved.
Reproductive BioMedicine Online  , DOI: ( /j.rbmo )
Copyright © 2015 Reproductive Healthcare Ltd. Terms and Conditions

3. Figure 2
Spermatogenesis. Primordial germ cells, proliferative type A spermatogonia, undergo a series of mitotic divisions. One of the daughter cells renews the stock of type A spermatogonia, the other becomes a type B spermatogonia with incomplete cytoplasmic separation. These divide and their daughter cells migrate towards the lumen. Type B spermatogonial cells enter the meiotic pathway. Meiosis involves two cell divisions to produce haploid spermatids with only one round of DNA synthesis. Finally, spermatids differentiate into spermatozoa and are released into the lumen of tubule.
Reprinted with permission, Cleveland Clinic Center for Medical Art & Photography © All Rights Reserved.
Reproductive BioMedicine Online  , DOI: ( /j.rbmo )
Copyright © 2015 Reproductive Healthcare Ltd. Terms and Conditions

4. Figure 3
DNA damage and DNA repair mechanisms. Common DNA damaging agents (left), DNA lesion induced by these agents (middle), and the most relevant DNA repair mechanisms responsible for the removal of the lesions (right).
Reprinted with permission, Cleveland Clinic Center for Medical Art & Photography © All Rights Reserved.
Reproductive BioMedicine Online  , DOI: ( /j.rbmo )
Copyright © 2015 Reproductive Healthcare Ltd. Terms and Conditions