Preface

Chapter 9 **The Role of Human Semen as an Early and Reliable Tool of**

Chapter 10 **Interacytoplasmic Morphologically Selected Sperm Injection: A Tool for Selecting the Best Sperm in Real Time 203**

Chapter 11 **Advanced Label-Free Optical Methods for Spermatozoa Quality**

Annalisa De Angelis, Maria Antonietta Ferrara, Giuseppe Coppola

Yona Barak and Adrian Ellenbogen

**Assessment and Selection 219**

and Anna Chiara De Luca

Stefano Lorenzetti

**VI** Contents

**Environmental Impact Assessment on Human Health 173** Luigi Montano, Paolo Bergamo, Maria Grazia Andreassi and

> Many aspects of modern life—such as industrialization, environmental pollutants, stress fac‐ tors, and poor life quality—have been blamed for declining the sperm quality and increasing the infertility rate. The alarming revelation is that infertility causes are still poorly under‐ stood, thus putting urgency to increase research effort toward male reproductive health.

> Spermatozoa are derived from spermatogenesis, an orchestrated developmental process, which occurs in a continuous or seasonal fashion, depending on the species. This process is centrally governed by hypothalamic networks (i.e., kisspeptin and gonadotropin-releasing hormone (GnRH) neurons), which sustain gonadotropin discharge and gonadal steroids, and by a complex network of intratesticular cell-to-cell communications. After mitotic and meiotic divisions, spermatogonia—diploid cells—forms the round spermatids. Haploid spermatid is a round, unflagellated cell that looks nothing like the mature vertebrate sperm; to become spermatozoa, in fact, spermatids undergo extensive morphological and biochemi‐ cal transformations in the postmeiotic phase (spermiogenesis). Such a process requires the formation of acrosome and flagellum, the deep remodeling of chromatin, and the reorgani‐ zation of cytoplasmatic/cytoskeleton architecture. All these guises make spermatozoa very peculiar cells, differing from others in physiology and function. After spermiogenesis, the journey through both male and female reproductive tracts prepares the sperm to meet and bind with the egg, ensuring that an intact male genome reaches the site of fertilization.

> Spermatogenesis and spermatozoa are highly sensitive to energy availability, stress, life‐ style, temperature, pollutants, heavy metals or endocrine disruptor chemicals that act at sev‐ eral levels along the hypothalamus-pituitary-gonad axis. All these aspects deeply impact critical quality parameters of semen—such as the production, motility, and/or fertilizing ability of spermatozoa—not only its genetic information but also its epigenetic blueprint. Even more worrying is that environmental-induced genetic and epigenetic damage may have transgenerational effects with an increased incidence of diseases in the next generation. Thus, the functional role of spermatozoa has been recently revised. Once considered just a "carrier" for male haploid genome during fertilization, nowadays spermatozoa store "pater‐ nal experience" and actively contribute to the embryo development and to the offspring health. Therefore, not only morphological feature, but also epigenetic signature of spermato‐ zoa, is critical to ensure their proper physiological activity.

> The book aims at providing basic and innovative concepts linked to sperm quality, in both physiological and pathological conditions. In particular, a part of the book addresses its at‐ tention on methods usually used in clinical practice to assess morphological parameters of sperm cells in infertile patients.

This book is organized into 11 chapters. Chapter 1 is a general overview on spermatogenesis and spermatozoa features and includes the upcoming perspectives on spermatozoa func‐ tion. Then, four chapters concern the spermatogenesis progression in vertebrates and sperm quality assessment. In detail, similarities and differences in spermatogenesis among verte‐ brates have been reported in Chapter 2, which provides an overview on germ cell differen‐ tiation in urodele amphibians, pointing out the lobular organization of urodele testis. Chapter 3 is a comprehensive overview of the molecular markers specifically expressed at different stages of spermatogenesis in mammals and describes the upcoming possibility to gain/regenerate a complete spermatogenesis in vitro. Then, Chapter 4 focuses on the experi‐ mental procedures aimed at analyzing the classical morphological features of spermatozoa in conventional assays. Chapter 5 deeply analyzes the ultrastructure of spermatozoa in health and disease and points out the requirement of proper chromatin structure as a critical step to preserve embryo health.

The preservation of sperm functions depends on the composition of the surrounding micro‐ environment. In this respect, Chapter 6 discusses the contribution of male accessory glands in sperm physiology and underlines how seminal plasma is rich in accessory gland-derived biomarkers and how the interaction between this fluid and spermatozoa impacts DNA, membrane and organelle integrity in sperm cells.

Upcoming evidence revealed the effects of lifestyle and environment on the preservation of reproductive health, the sperm quality and the epigenetic signature of spermatozoa. The im‐ pact of oxidative stress—the main cause of cell damage—and of environmental factors on the human semen is well discussed in Chapters 7 and 8, respectively. Chapter 9, in particu‐ lar, suggests that reproductive health may be considered as an early signal of environmental pressure, suggesting an innovative program of health surveillance in environmental risk areas. The last two chapters of the book are focused on conventional clinical practice of as‐ sisted reproduction—the ICSI method (Chapter 10)—and advanced label-free optical meth‐ od to assess and select high-quality spermatozoa (Chapter 11).

We would like to thank all the authors for their valuable contributions and for the construc‐ tive interplay throughout the editorial process.

> **Rosaria Meccariello** Department of Movement Sciences and Wellness "Parthenope" University of Naples Italy

#### **Rosanna Chianese**

**Chapter 1**

**Provisional chapter**

**Introductory Chapter: Spermatozoa - Facts and**

**1. Spermatozoa morphology and physiology: an introduction**

Sperm cells (SPZ) are derived from spermatogenesis, a highly regulated developmental process starting from diploid precursors—spermatogonial stem cells—that undergo strictly orchestrated mitotic and meiotic divisions to form round spermatids. Extensive morphological and biochemical transformations in post-meiotic phase are required to differentiate round spermatids into highly specialized SPZ [1–3]. Thus, during spermiogenesis, the round spermatids transform into specialized and polarized cells that exhibit: at proximal end, the head containing an elongated and transcriptionally inactive nucleus which is apically surrounded by the Golgi-derived acrosome, and at the distal end, a tail surrounded at its proximal midpieces by mitochondrial sheet. A part from acrosome biogenesis, the spermiogenesis accounts for a radical chromatin remodeling that causes genome silencing [4] through histone replacement with transition proteins, firstly, and protamines later, to obtain a tightly packaged chromatin [5]. In parallel, a global reorganization of cytoplasmatic/cytoskeleton architecture drives elongation step with the development of a flagellum and the formation of cytoplasmic

In mammals, two post-testicular maturational events are required so that SPZ may reach their fertilization ability: the former occurring in the epididymis, the latter in female reproductive tract. The epididymis is a long convoluted tubule characterized by three main morphologically and functionally distinct regions (proximal caput, elongated corpus, and distal cauda) [6]. It represents the extracellular microenvironment in which a fine crosstalk between SPZ and epididymis epithelial cells takes place, generally through vesicles known as epididymosomes [7]. During their journey along the epididymis, SPZ remodel the lipid content of plasma membrane, especially cholesterol, receive a rich and complex repertoire of protein and non-coding RNAs (ncRNAs), especially microRNAs (miRNAs), long non-coding RNA

**Introductory Chapter: Spermatozoa - Facts and** 

DOI: 10.5772/intechopen.75674

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

© 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use,

distribution, and reproduction in any medium, provided the original work is properly cited.

Rosanna Chianese and Rosaria Meccariello

Additional information is available at the end of the chapter

Rosanna Chianese and Rosaria MeccarielloAdditional information is available at the end of the chapter

http://dx.doi.org/10.5772/intechopen.75674

droplets which contain the excess cytoplasm.

**Perspectives**

**Perspectives**

Department of Experimental Medicine University of Campania "Luigi Vanvitelli" Italy

#### **Introductory Chapter: Spermatozoa - Facts and Perspectives Introductory Chapter: Spermatozoa - Facts and Perspectives**

DOI: 10.5772/intechopen.75674

Rosanna Chianese and Rosaria Meccariello

Additional information is available at the end of the chapter Rosanna Chianese and Rosaria MeccarielloAdditional information is available at the end of the chapter

http://dx.doi.org/10.5772/intechopen.75674

This book is organized into 11 chapters. Chapter 1 is a general overview on spermatogenesis and spermatozoa features and includes the upcoming perspectives on spermatozoa func‐ tion. Then, four chapters concern the spermatogenesis progression in vertebrates and sperm quality assessment. In detail, similarities and differences in spermatogenesis among verte‐ brates have been reported in Chapter 2, which provides an overview on germ cell differen‐ tiation in urodele amphibians, pointing out the lobular organization of urodele testis. Chapter 3 is a comprehensive overview of the molecular markers specifically expressed at different stages of spermatogenesis in mammals and describes the upcoming possibility to gain/regenerate a complete spermatogenesis in vitro. Then, Chapter 4 focuses on the experi‐ mental procedures aimed at analyzing the classical morphological features of spermatozoa in conventional assays. Chapter 5 deeply analyzes the ultrastructure of spermatozoa in health and disease and points out the requirement of proper chromatin structure as a critical

The preservation of sperm functions depends on the composition of the surrounding micro‐ environment. In this respect, Chapter 6 discusses the contribution of male accessory glands in sperm physiology and underlines how seminal plasma is rich in accessory gland-derived biomarkers and how the interaction between this fluid and spermatozoa impacts DNA,

Upcoming evidence revealed the effects of lifestyle and environment on the preservation of reproductive health, the sperm quality and the epigenetic signature of spermatozoa. The im‐ pact of oxidative stress—the main cause of cell damage—and of environmental factors on the human semen is well discussed in Chapters 7 and 8, respectively. Chapter 9, in particu‐ lar, suggests that reproductive health may be considered as an early signal of environmental pressure, suggesting an innovative program of health surveillance in environmental risk areas. The last two chapters of the book are focused on conventional clinical practice of as‐ sisted reproduction—the ICSI method (Chapter 10)—and advanced label-free optical meth‐

We would like to thank all the authors for their valuable contributions and for the construc‐

**Rosaria Meccariello**

**Rosanna Chianese**

Italy

Italy

Department of Movement Sciences and Wellness

"Parthenope" University of Naples

Department of Experimental Medicine University of Campania "Luigi Vanvitelli"

step to preserve embryo health.

VIII Preface

membrane and organelle integrity in sperm cells.

tive interplay throughout the editorial process.

od to assess and select high-quality spermatozoa (Chapter 11).
